Opel Insignia Owners & Service Manuals

Opel Insignia: Diagnostic Information and Procedures

DTC B1405, B1825, B2355, B2365, or B2375 (Driver Seat)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1405

Control Module Voltage Reference Output 2 Circuit

DTC B1825

Seat Recline Position Sensor Circuit

DTC B2355

Seat Front Vertical Position Sensor Circuit

DTC B2365

Seat Rear Vertical Position Sensor Circuit

DTC B2375

Seat Assembly Horizontal Position Sensor Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

Circuit Description

The seat memory control module monitors the position of the seat motors by using hall effect position sensors which are an internal part of each motor. The module supplies each sensor with a 12 V reference circuit only when any seat motor is active, and a low side signal circuit. During seat motor operation, the hall effect position sensor provides a determined number of pulse signals for every revolution of the motor shaft. The scan tool displays these pulse signals as counts that range from 0 - 65, 535. The module counts the feedback pulses from each sensor to determine seat position and end of travel limits for each of the seat motors. High scan tool count values indicate forward or upward seat positions while low count values indicate rearward or downward seat positions.

Conditions for Running the DTC

  • Any seat motor must be active.
  • DTC B1325 must not be present.
  • Module battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

The seat memory control module does not detect position sensor movement or pulse signals while the adjuster motor is active. The following conditions will set this DTC:

B1405 02

The seat memory control module detects a short to ground or an open on the 12 V reference circuit.

B1825 01, B2355 01, B2365 01, or B2375 01

The seat memory control module detects a voltage greater than 5 V on the sensor signal circuit.

B1825 06, B2355 06, B2365 06, or B2375 06

The seat memory control module detects a short to ground or an open on the sensor signal circuit.

Action Taken When the DTC Sets

  • With a short to ground or an open circuit, the seat memory control module disables the memory recall and easy exit/entry action commands of the motor monitored by the sensor. The motor will respond to manual position commands.
  • With a short to battery voltage, the seat memory control module disables the memory recall and easy exit/entry action commands for all four seat motors. The motors will respond to manual position commands.

Conditions for Clearing the DTC

  • The current DTC clears when the fault is no longer present and the power mode changes to OFF then back to ACC or RUN.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

Driver Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate driver seat motor listed below for which the DTC set:

  • M50D Seat Front Vertical Motor - Driver
  • M55D Seat Rear Vertical Motor - Driver
  • M51D Seat Horizontal Motor - Driver
  • M56D Seat Recline Motor - Driver

2. Ignition ON.

3. Test for greater than 10.8 V between the appropriate 12 V reference circuit listed below and ground while pressing any power seat switch.

  • M50D Seat Front Vertical Motor - Driver terminal 2
  • M55D Seat Rear Vertical Motor - Driver terminal 4
  • M51D Seat Horizontal Motor - Driver terminal 4
  • M56D Seat Recline Motor - Driver terminal 2
  • If 10.8 V or less
  1. Ignition OFF, disconnect the X5 harness connector at the K40D Seat Memory Control Module - Driver.
  2. Test for infinite resistance between the 12 V reference circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the 12 V reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40D Seat Memory Control Module - Driver.
  • Go to next step: If greater than 10.8 V

4. Test for 0.2 - 2 V between the appropriate signal circuit listed below and ground.

  • M50D Seat Front Vertical Motor - Driver terminal 4
  • M55D Seat Rear Vertical Motor - Driver terminal 2
  • M51D Seat Horizontal Motor - Driver terminal 2
  • M56D Seat Recline Motor - Driver terminal 4
  • If less than 0.2 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40D Seat Memory Control Module - Driver.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40D Seat Memory Control Module - Driver.
  • If greater than 2 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40D Seat Memory Control Module - Driver, ignition ON.
  2. Test for less than 1 V between each signal circuit listed below and ground.
    • Front vertical sensor terminal 12
    • Seat horizontal sensor terminal 11
    • Rear vertical sensor terminal 25
    • Seat recline sensor terminal 26
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K40D Seat Memory Control Module - Driver.
  • Go to next step: If between 0.2 - 2 V

5. Test or replace the seat motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Front Seat Tilt Adjuster Actuator Replacement
  • Driver or Passenger Seat Vertical Adjuster Actuator Replacement
  • Driver or Passenger Seat Recliner Actuator Replacement (Except GS) or Driver or Passenger Seat Recliner Actuator Replacement (GS)
  • Control Module References for K40D Seat Memory Control Module - Driver replacement, programming and setup

DTC B1405, B1825, B2355, B2365, or B2375 (Passenger Seat)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1405

Control Module Voltage Reference Output 2 Circuit

DTC B1825

Seat Recline Position Sensor Circuit

DTC B2355

Seat Front Vertical Position Sensor Circuit

DTC B2365

Seat Rear Vertical Position Sensor Circuit

DTC B2375

Seat Assembly Horizontal Position Sensor Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

Circuit Description

The seat memory control module monitors the position of the seat motors by using hall effect position sensors which are an internal part of each motor. The module supplies each sensor with a 12 V reference circuit only when any seat motor is active, and a low side signal circuit. During seat motor operation, the hall effect position sensor provides a determined number of pulse signals for every revolution of the motor shaft. The scan tool displays these pulse signals as counts that range from 0 - 65, 535. The module counts the feedback pulses from each sensor to determine seat position and end of travel limits for each of the seat motors. High scan tool count values indicate forward or upward seat positions while low count values indicate rearward or downward seat positions.

Conditions for Running the DTC

  • Any seat motor must be active.
  • DTC B1325 must not be present.
  • Module battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

The seat memory control module does not detect position sensor movement or pulse signals while the adjuster motor is active. The following conditions will set this DTC:

B1405 02

The seat memory control module detects a short to ground or an open on the 12 V reference circuit.

B1825 01, B2355 01, B2365 01, or B2375 01

The seat memory control module detects a voltage greater than 5 V on the sensor signal circuit.

B1825 06, B2355 06, B2365 06, or B2375 06

The seat memory control module detects a short to ground or an open on the sensor signal circuit.

Action Taken When the DTC Sets

  • With a short to ground or an open circuit, the seat memory control module disables the memory recall and easy exit/entry action commands of the motor monitored by the sensor. The motor will respond to manual position commands.
  • With a short to battery voltage, the seat memory control module disables the memory recall and easy exit/entry action commands for all four seat motors. The motors will respond to manual position commands.

Conditions for Clearing the DTC

  • The current DTC clears when the fault is no longer present and the power mode changes to OFF then back to ACC or RUN.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate passenger seat motor listed below for which the DTC set:

  • M50P Seat Front Vertical Motor - Passenger
  • M55P Seat Rear Vertical Motor - Passenger
  • M51P Seat Horizontal Motor - Passenger
  • M56P Seat Recline Motor - Passenger

2. Ignition ON.

3. Test for greater than 10.8 V between the 12 V reference circuit listed below and ground while pressing any power seat switch.

  • M50P Seat Front Vertical Motor - Driver terminal 2
  • M55P Seat Rear Vertical Motor - Driver terminal 4
  • M51P Seat Horizontal Motor - Driver terminal 4
  • M56P Seat Recline Motor - Driver terminal 2
  • If 10.8 V or less
  1. Ignition OFF, disconnect the X5 harness connector at the K40P Seat Memory Control Module - Passenger.
  2. Test for infinite resistance between the 12 V reference circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the 12 V reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40P Seat Memory Control Module - Passenger.
  • Go to next step: If greater than 10.8 V

4. Test for 0.2 - 2 V between the appropriate signal circuit listed below and ground.

  • M50P Seat Front Vertical Motor - Driver terminal 4
  • M55P Seat Rear Vertical Motor - Driver terminal 2
  • M51P Seat Horizontal Motor - Driver terminal 2
  • M56P Seat Recline Motor - Driver terminal 4
  • If less than 0.2 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40P Seat Memory Control Module - Passenger.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40P Seat Memory Control Module - Passenger.
  • If greater than 2 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40P Seat Memory Control Module - Passenger, ignition ON.
  2. Test for less than 1 V between each signal circuit listed below and ground.
    • Front vertical sensor terminal 12
    • Seat horizontal sensor terminal 11
    • Rear vertical sensor terminal 25
    • Seat recline sensor terminal 26
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K40P Seat Memory Control Module - Passenger.
  • Go to next step: If between 0.2 - 2 V

5. Test or replace the seat motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Front Seat Tilt Adjuster Actuator Replacement
  • Driver or Passenger Seat Vertical Adjuster Actuator Replacement
  • Driver or Passenger Seat Recliner Actuator Replacement (Except GS) or Driver or Passenger Seat Recliner Actuator Replacement (GS)
  • Control Module References for K40P Seat Memory Control Module - Passenger replacement, programming and setup

DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820 (Driver Seat)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1735

Seat Front Up Switch Circuit

DTC B1740

Seat Front Down Switch Circuit

DTC B1745

Seat Rear Up Switch Circuit

DTC B1750

Seat Rear Down Switch Circuit

DTC B1755

Seat Assembly Forward Switch Circuit

DTC B1760

Seat Assembly Rearward Switch Circuit

DTC B1815

Seat Recline Forward Switch Circuit

DTC B1820

Seat Recline Rearward Switch Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

Power Seats

1. Power seat is inoperative

Circuit/System Description

The seat memory control module supplies a reference voltage to each signal circuit of the driver seat adjuster switch. When the power seat switches are pressed, the appropriate signal circuit from the seat memory control module is pulled low through the switch contacts indicating the power seat command.

The seat memory control module then commands the driver seat to move in response to the switch signals.

Conditions for Running the DTC

  • DTC B1325 must not be present.
  • Module battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

  • If a seat or lumbar switch circuit is active in one direction and the switch for the opposite direction is pressed, this DTC will set.
  • A short to ground on a switch signal circuit.

Action Taken When the DTC Sets

  • A motor output driven in response to a switch considered failed, is deactivated for both directions.
  • All memory recall commands are ignored.
  • The seat memory control module will respond to any other switch signal that has not set a DTC.

Conditions for Clearing the DTC

  • The current DTC will clear and set the DTC to history, when the fault is no longer present and the ignition is cycled OFF then back to ACC or RUN.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Diagnostic Aids

  • If one of the switch signal circuits is shorted to ground, multiple DTCs will set.
  • If a switch is stuck in one direction and the switch is pressed in the opposite direction, a single DTC will set.

Reference Information

Schematic Reference

Driver Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the scan tool seat switch parameters listed below change between Inactive and Forward/Rearward or UP/Down when pressing the appropriate seat directional switch.

  • Driver Seat Cushion Front Vertical Switch
  • Driver Seat Cushion Rear Vertical Switch
  • Driver Seat Horizontal Switch
  • Driver Seat Back Switch
  • If the parameter does not change

Refer to Circuit/System Testing.

  • Go to next step: If the parameter changes

3. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S64D Seat Adjuster Switch - Driver.

2. Clear present DTCs to enable system.

3. Verify that all scan tool driver seat switch parameters listed below are Inactive:

  • Driver Seat Cushion Front Vertical Switch
  • Driver Seat Cushion Rear Vertical Switch
  • Driver Seat Horizontal Switch
  • Driver Seat Back Switch
  • If not Inactive
  1. Ignition OFF, disconnect the X5 harness connector at the K40D Seat Memory Control Module - Driver, ignition ON.
  2. Test for infinite resistance between the appropriate signal circuit terminal listed below and ground:
    • Front vertical up switch terminal A
    • Front vertical down switch terminal K
    • Rear vertical up switch terminal F
    • Rear vertical down switch terminal J
    • Horizontal forward switch terminal D
    • Horizontal rearward switch terminal C
    • Recline forward switch terminal H
    • Recline rearward switch terminal G
    • If less than infinite resistance, repair the short to ground on the circuit.
    • If infinite resistance, replace the K40D Seat Memory Control Module - Driver.
  • Go to next step: If Inactive

4. Install a 3 A fused jumper wire between the appropriate signal circuit terminal listed below and the ground circuit terminal E.

  • Front vertical up switch terminal A
  • Front vertical down switch terminal K
  • Rear vertical up switch terminal F
  • Rear vertical down switch terminal J
  • Horizontal forward switch terminal D
  • Horizontal rearward switch terminal C
  • Recline forward switch terminal H
  • Recline rearward switch terminal G

5. Verify the appropriate scan tool seat switch parameter is Forward/Rearward or UP/Down.

  • If not Forward/Rearward or UP/Down
  1. Ignition OFF, disconnect the X5 harness connector at the K40D Seat Memory Control Module - Driver, ignition ON.
  2. Test for less than 1 V between the signal circuit terminal and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V
  3. Ignition OFF.
  4. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40D Seat Memory Control Module - Driver.
  • Go to next step: If Forward/Rearward or UP/Down

6. Test or replace the S64D Seat Adjuster Switch - Driver.

Component Testing

Seat Adjuster Switch Test

1. Ignition OFF, disconnect the harness connector at the S64D Seat Adjuster Switch - Driver.

2. Test for infinite resistance between the ground terminal E and each signal terminal with the switch in the open position.

  • If less than infinite resistance

Replace the S64D Seat Adjuster Switch - Driver.

  • Go to next step: If infinite resistance

3. Test for less than 2 Ω between the ground terminal E and each signal terminal with the appropriate switch in the closed position.

  • If 2 Ω or greater

Replace the S64D Seat Adjuster Switch - Driver.

  • Go to next step: If less than 2 Ω

4. All OK.

Repair Instructions

  • Perform the Diagnostic Repair Verification after completing the repair.

    Driver or Passenger Seat Adjuster Switch Replacement

  • Control Module References for K40D Seat Memory Control Module - Driver replacement, programming and setup

DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820 (Passenger Seat)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1735

Seat Front Up Switch Circuit

DTC B1740

Seat Front Down Switch Circuit

DTC B1745

Seat Rear Up Switch Circuit

DTC B1750

Seat Rear Down Switch Circuit

DTC B1755

Seat Assembly Forward Switch Circuit

DTC B1760

Seat Assembly Rearward Switch Circuit

DTC B1815

Seat Recline Forward Switch Circuit

DTC B1820

Seat Recline Rearward Switch Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

Power Seats

1. Power seat is inoperative

Circuit/System Description

The seat memory control module supplies a reference voltage to each signal circuit of the passenger seat adjuster switch. When the power seat switches are pressed, the appropriate signal circuit from the seat memory control module is pulled low through the switch contacts indicating the power seat command.

The seat memory control module then commands the passenger seat to move in response to the switch signals.

Conditions for Running the DTC

  • DTC B1325 must not be present.
  • Module battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

  • If a seat or lumbar switch circuit is active in one direction and the switch for the opposite direction is pressed, this DTC will set.
  • A short to ground on a switch signal circuit.

Action Taken When the DTC Sets

  • A motor output driven in response to a switch considered failed, is deactivated for both directions.
  • All memory recall commands are ignored.
  • The seat memory control module will respond to any other switch signal that has not set a DTC.

Conditions for Clearing the DTC

  • The current DTC will clear and set the DTC to history, when the fault is no longer present and the ignition is cycled OFF then back to ACC or RUN.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Diagnostic Aids

  • If one of the switch signal circuits is shorted to ground, multiple DTCs will set.
  • If a switch is stuck in one direction and the switch is pressed in the opposite direction, a single DTC will set.

Reference Information

Schematic Reference

Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Clear present DTCs to enable system.

3. Verify the scan tool seat switch parameters listed below change between Inactive and Forward/Rearward or UP/Down when pressing the appropriate seat directional switch.

  • Passenger Seat Cushion Front Vertical Switch
  • Passenger Seat Cushion Rear Vertical Switch
  • Passenger Seat Horizontal Switch
  • Passenger Seat Back Switch
  • If the parameter does not change

Refer to Circuit/System Testing.

  • Go to next step: If the parameter changes

4. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S64P Seat Adjuster Switch - Passenger.

2. Verify that all scan tool passenger seat switch parameters listed below are Inactive:

  • Passenger Seat Cushion Front Vertical Switch
  • Passenger Seat Cushion Rear Vertical Switch
  • Passenger Seat Horizontal Switch
  • Passenger Seat Back Switch
  • If not Inactive
  1. Ignition OFF, disconnect the X5 harness connector at the K40P Seat Memory Control Module - Passenger, ignition ON.
  2. Test for infinite resistance between the appropriate signal circuit terminal listed below and ground:
    • Front vertical up switch terminal K
    • Front vertical down switch terminal A
    • Rear vertical up switch terminal J
    • Rear vertical down switch terminal F
    • Horizontal forward switch terminal D
    • Horizontal rearward switch terminal C
    • Recline forward switch terminal H
    • Recline rearward switch terminal G
    • If less than infinite resistance, repair the short to ground on the circuit.
    • If infinite resistance, replace the K40P Seat Memory Control Module - Passenger.
  • Go to next step: If Inactive

3. Install a 3 A fused jumper wire between the appropriate signal circuit terminal listed below and the ground circuit terminal E.

  • Front vertical up switch terminal K
  • Front vertical down switch terminal A
  • Rear vertical up switch terminal J
  • Rear vertical down switch terminal F
  • Horizontal forward switch terminal D
  • Horizontal rearward switch terminal C
  • Recline forward switch terminal H
  • Recline rearward switch terminal G

4. Verify the appropriate scan tool seat switch parameter is Forward/Rearward or UP/Down.

  • If not Forward/Rearward or UP/Down
  1. Ignition OFF, disconnect the X5 harness connector at the K40P Seat Memory Control Module - Passenger, ignition ON.
  2. Test for less than 1 V between the signal circuit terminal and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V
  3. Ignition OFF.
  4. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40P Seat Memory Control Module - Passenger.
  • Go to next step: If Forward/Rearward or UP/Down

5. Test or replace the S64P Seat Adjuster Switch - Passenger.

Component Testing

Seat Adjuster Switch Test

1. Ignition OFF, disconnect the harness connector at the S64P Seat Adjuster Switch - Passenger.

2. Test for infinite resistance between the ground terminal E and each signal terminal with the switch in the open position.

  • If less than infinite resistance

Replace the S64P Seat Adjuster Switch - Passenger.

  • Go to next step: If infinite resistance

3. Test for less than 2 Ω between the ground terminal E and each signal terminal with the appropriate switch in the closed position.

  • If 2 Ω or greater

Replace theS64P Seat Adjuster Switch - Passenger.

  • Go to next step: If less than 2 Ω

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Adjuster Switch Replacement
  • Control Module References for K40P Seat Memory Control Module - Passenger replacement, programming and setup

DTC B183B or B183C

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B183B

Seat Lumbar Support Switch Signal Circuit

DTC B183C

Seat Bolster/Massage Switch Signal Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

Power Seats

1. The seat lumbar support function is inoperative.
2. The seat side bolster/massage function is inoperative.

Circuit/System Description

Ground is supplied to the seat lumbar support and the seat back side bolster switches. Each switch is also supplied with a 5 V reference and signal circuits from the seat memory control module. The reference voltage is applied to a resistive network internal to the switches. When a switch is pressed, the output of the resistive network results in a voltage drop on the signal circuit to the seat memory control module indicating the lumbar, bolster, or massage request. In response to this signal, the seat memory control module sends a LIN serial data message to the seat bolster memory control module commanding it to perform the required pneumatic movements.

Conditions for Running the DTC

  • DTC B1327 must not be present.
  • Battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

B183B 06

If the seat memory control module detects a short to ground or an open in the seat lumbar support switch signal circuit this DTC will set.

B183B 08

If the seat memory control module detects an invalid signal on the seat lumbar support switch signal circuit this DTC will set.

B183B 59

The seat memory control module detects a stuck lumbar support switch for a given amount of time.

B183C 06

If the seat memory control module detects a short to ground or an open in the seat bolster/massage switch signal circuit this DTC will set.

B183C 08

If the seat memory control module detects an invalid signal on the seat bolster/massage switch signal circuit this DTC will set.

B183C 59

The seat memory control module detects a stuck seat bolster or massage switch for a given amount of time.

Actions Taken When the DTC Sets

B183B 06, B183B 08, or B183B 59

  • Current and history DTCs are set.
  • All seat lumbar support commands and are ignored.

B183C 06, B183C 08, or B183C 59

  • Current and history DTCs are set.
  • All seat bolster and massage commands and are ignored.

Conditions for Clearing the DTCs

  • The DTC automatically clears when the switch circuit setting the DTC is no longer active.
  • A history DTC will clear once 50 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify DTC B183B 59 is not set as a current DTC.

  • If the DTC is set current

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If the DTC is not set current

3. Verify DTC B183C 59 is not set as a current DTC.

  • If the DTC is set current

Replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If the DTC is not set current

4. Verify DTC B183B 06 or B183B 08 is not set.

  • If either DTC is set

Refer to Circuit/System Testing - DTC B183B Lumbar Switch Circuit Test.

  • Go to next step: If either DTC is not set

5. Verify DTC B183C 06 or B183C 08 is not set.

  • If either DTC is set

Refer to Circuit/System Testing - DTC B183C Seat Back Side Bolster Switch Circuit Test.

  • Go to next step: If either DTC is not set

6. All OK.

Circuit/System Testing

DTC B183B Lumbar Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat lumbar support switch listed below. It may take up to 2 min for all vehicle systems to power down.

  • S65D Seat Lumbar Support Switch - Driver
  • S65P Seat Lumbar Support Switch - Passenger

2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition ON.

4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and ground.

  • If less than 4.8 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module.
  2. Test for infinite resistance between the 5 V reference circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the 5 V reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • If greater than 5.2 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module, ignition ON.
  2. Test for less than 1 V between the 5 V reference circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K40 Seat Memory Control Module.
  • Go to next step: If between 4.8 - 5.2 V

5. Test for less than 1 V between the signal circuit terminal 2 and ground.

  • If 1 V or greater
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module, ignition ON.
  2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K40 Seat Memory Control Module.
  • Go to next step: If less than 1 V

NOTE: With the seat lumbar support switch disconnected, DTC B183B with symptom byte 06 may already be set. However, the purpose of this test is to verify DTC B183B will set with symptom byte 08 when the signal circuit is shorted to voltage.

6. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 3 and the signal circuit terminal 2.

7. Verify DTC B183B 08 is set.

  • If DTC B183B 08 is not set
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • Go to next step: If DTC B183B 08 is set

8. Test or replace the S65 Seat Lumbar Support Switch.

DTC B183C Seat Back Side Bolster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the seat back side bolster adjuster switch listed below. It may take up to 2 min for all vehicle systems to power down.

  • S66D Seat Back Side Bolster Adjuster Switch - Driver
  • S66P Seat Back Side Bolster Adjuster Switch - Passenger

2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition ON.

4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and ground.

  • If less than 4.8 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module.
  2. Test for infinite resistance between the 5 V reference circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the 5 V reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • If greater than 5.2 V
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module, ignition ON.
  2. Test for less than 1 V between the 5 V reference circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K40 Seat Memory Control Module.
  • Go to next step: If between 4.8 - 5.2 V

5. Test for less than 1 V between the signal circuit terminal 2 and ground.

  • If 1 V or greater
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module, ignition ON.
  2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K40 Seat Memory Control Module.
  • Go to next step: If less than 1 V

NOTE: With the seat back side bolster adjuster switch disconnected, DTC B183C with symptom byte 06 may already be set. However, the purpose of this test is to verify DTC B183C will set with symptom byte 08 when the signal circuit is shorted to voltage.

6. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 3 and the signal circuit terminal 2.

7. Verify DTC B183C 08 is set.

  • If DTC B183C 08 is not set
  1. Ignition OFF, disconnect the X5 harness connector at the K40 Seat Memory Control Module.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • Go to next step: If DTC B183C 08 is set

8. Test or replace the S66 Seat Back Side Bolster Adjuster Switch.

Component Testing

Seat Lumbar Support Switch

1. Ignition OFF, disconnect the harness connector at the S65 Seat Lumbar Support Switch.

2. Test for infinite resistance between the signal terminal 2 and the ground terminal 1 with the switch in the open position.

  • If less than infinite resistance

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If infinite resistance

3. Test for 252 - 308 Ω between the signal terminal 2 and the 5 V reference terminal 3.

  • If not between 252 - 308 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 252 - 308 Ω

4. Test for 146 - 178 Ω between the signal terminal 2 and the ground terminal 1 while pressing the lumbar rearward switch.

  • If not between 146 - 178 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 146 - 178 Ω

5. Test for 459 - 561 Ω between the signal terminal 2 and the ground terminal 1 while pressing the lumbar forward switch.

  • If not between 459 - 561 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 459 - 561 Ω

6. Test for 1134 - 1386 Ω between the signal terminal 2 and the ground terminal 1 while pressing the lumbar down switch.

  • If not between 1134 - 1386 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 1134 - 1386 Ω

7. Test for 3.02k - 3.7 kΩ between the signal terminal 2 and the ground terminal 1 while pressing the lumbar up switch.

  • If not between 3.02k - 3.7 kΩ

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 3.02k - 3.7 kΩ

8. All OK.

Seat Back Side Bolster Switch

1. Ignition OFF, disconnect the harness connector at the S66 Seat Back Side Bolster Adjuster Switch.

2. Test for infinite resistance between the signal terminal 2 and the ground terminal 1 with the switch in the open position.

  • If less than infinite resistance

Replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If infinite resistance

3. Test for 252 - 308 Ω between the signal terminal 2 and the 5 V reference terminal 3.

  • If not between 252 - 308 Ω

Replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If between 252 - 308 Ω

4. Test for 459 - 561 Ω between the signal terminal 2 and the ground terminal 1 while pressing the seat back side bolster inflate switch.

  • If not between 459 - 561 Ω

Replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If between 459 - 561 Ω

5. Test for 1134 - 1386 Ω between the signal terminal 2 and the ground terminal 1 while pressing the seat back side bolster deflate switch.

  • If not between 1134 - 1386 Ω

Replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If between 1134 - 1386 Ω

6. Test for 3.02k - 3.7 kΩ between the signal terminal 2 and the ground terminal 1 while pressing the massage switch.

  • If not between 3.02k - 3.7 kΩ

Replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If between 3.02k - 3.7 kΩ

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Lumbar Control Switch Replacement
  • Control Module References for K40D Seat Memory Control Module - Driver or K40P Seat Memory Control Module - Passenger replacement, programming, and setup

DTC B2755 or B2765

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B2755

Seat Memory Select Switch Circuit

DTC B2765

Seat Memory Set Switch Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

1. Memory recall is inoperative

Circuit/System Description

Low reference is supplied to the seat memory switch from the seat memory control module. When a memory switch is pressed, the signal circuit from the seat memory control module is pulled low through the switch contacts and series of resistors indicating the memory recall request. In response to this signal, the seat memory control module commands the appropriate seat motors to move to the prerecorded seat positions stored in memory.

Conditions for Running the DTC

  • DTC B1327 must not be present.
  • Battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

B2755 01

If the seat memory control module detects a short to voltage on the memory seat switch signal circuit this DTC will set.

B2755 02

If the seat memory control module detects a short to ground on the memory seat switch signal circuit this DTC will set.

B2755 59

The seat memory control module detects a stuck Memory 1 or Memory 2 switch for a given amount of time.

B2765 59

If the memory set switch signal is active for greater than 15 s this DTC will set.

Actions Taken When the DTC Sets

  • Current and history DTCs are set.
  • All memory recall commands and are ignored.

Conditions for Clearing the DTCs

  • The DTC automatically clears when the switch circuit setting the DTC is no longer active.
  • A history DTC will clear once 50 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the appropriate scan tool Driver or Passenger Seat Memory Recall Switches parameter changes between Inactive and Memory 1 when pressing the memory 1 switch.

  • If the parameter does not change

Refer to Circuit/System Testing.

  • Go to next step: If the parameter changes

3. Verify the appropriate scan tool Driver or Passenger Seat Memory Recall Switches parameter changes between Inactive and Memory 2 when pressing the memory 2 switch.

  • If the parameter does not change

Refer to Circuit/System Testing.

  • Go to next step: If the parameter changes

4. Verify the appropriate scan tool Driver or Passenger Seat Memory Recall Switches parameter changes between Inactive and Exit when pressing the Exit switch.

  • If the parameter does not change

Refer to Circuit/System Testing.

  • Go to next step: If the parameter changes

5. Verify the appropriate scan tool Driver or Passenger Seat Memory Set Switch parameter changes between Inactive and Active when pressing the SET switch.

  • If the parameter does not change

Refer to Circuit/System Testing.

  • Go to next step: If the parameter changes

6. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate seat memory switch listed below, ignition ON.

  • S47D Seat Memory Switch - Driver
  • S47P Seat Memory Switch - Passenger

2. Press a power seat switch in order to wake up the K40 Seat Memory Control Module.

3. Test for 9 V or greater between each signal circuit terminal listed below and ground:

  • Memory set switch signal terminal 5
  • Memory switch signal terminal 6
  • If less than 9 V
  1. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • Go to next step: If 9 V or greater

4. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module, ignition ON.

5. Test for less than 1 V between each signal circuit terminal listed below and ground:

  • Memory set switch signal terminal 5
  • Memory switch signal terminal 6
  • If 1 V or greater

Repair the short to voltage on the circuit.

  • Go to next step: If less than 1 V

6. Test or replace the S47 Seat Memory Switch.

Component Testing

Seat Memory Switch

1. Ignition OFF, disconnect the harness connector at the S47 Seat Memory Switch.

2. Test for infinite resistance between each signal terminal listed below and the low reference terminal 1 with the switch in the open position.

  • Terminal 5
  • Terminal 6
  • If less than infinite resistance

Replace the S47 Seat Memory Switch.

  • Go to next step: If infinite resistance

3. Test for less than 4 Ω between the signal terminal 5 and the low reference terminal 1 while pressing the memory SET button.

  • If 4 Ω or greater

Replace the S47 Seat Memory Switch.

  • Go to next step: If less than 4 Ω

4. Test for 573 - 701 Ω between the signal terminal 6 and the low reference terminal 1 while pressing the memory 1 button.

  • If not between 573 - 701 Ω

Replace the S47 Seat Memory Switch.

  • Go to next step: If between 573 - 701 Ω

5. Test for 1800 - 2201 Ω between the signal terminal 6 and the low reference terminal 1 while pressing the memory 2 button.

  • If not between 1800 - 2201 Ω

Replace the S47 Seat Memory Switch.

  • Go to next step: If between 1800 - 2201 Ω

6. Test for 5.52k - 6.73 kΩ between the signal terminal 6 and the low reference terminal 1 while pressing the Exit button.

  • If not between 5.52k - 6.73 kΩ

Replace the S47 Seat Memory Switch.

  • Go to next step: If between 5.52k - 6.73 kΩ

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Front Seat Adjuster Memory Switch Replacement
  • Control Module References for K40D Seat Memory Control Module - Driver or K40P Seat
  • Memory Control Module - Passenger replacement, programming, and setup

DTC B3920

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B3920

Seat Motors Group 1 Ground Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Power Seats

1. All power seat and memory functions are inoperative.

Circuit/System Description

The seat memory control module controls the seat motors via half bridges that are connected to a power rail internal to the module. The seat memory control module connects all of the motor control circuits on the power rail to a common reference point whenever they are not in operation. The module monitors all seat motor control circuits for a shorted to ground or voltage before enabling any seat motor.

When a power seat switch is pressed or when a memory recall is requested, each seat motor receives battery voltage and ground from the seat memory control module via the motor control circuits. All motors are reversible, so the direction the motor rotates depends on which control circuit voltage is applied and which control circuit ground is applied. When the switch is operated in the opposite direction, the module reverses the polarity and applies voltage and ground to the opposite circuits to move the seat in the opposite direction.

Conditions for Running the DTC

  • DTC B1325 must not be present.
  • Module battery voltage must be between 9 - 16 V.

Conditions for Setting the DTC

B3920 00

Current out of the module does not match the current returning to the module from 1.5 - 5 A.

B3920 01

The voltage on any power rail 1 motor control circuit exceeds 2.78 V for 100 ms.

B3920 02

The voltage on any power rail 1 motor control circuit is below 1.47 V for 100 ms.

B3920 0B

The differential current measured through the high and low side of the power rail is within tolerance of each other, but the absolute current or an over-current has exceeded the maximum value.

Action Taken When the DTC Sets

The seat memory control module will not allow operation of any motor on the power rail for which the DTC was set.

Conditions for Clearing the DTC

  • The current DTC clears when the fault is no longer present and the power mode changes to ignition OFF then back to ignition ON.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Testing

B3920 01 or B3920 02

1. Ignition OFF, disconnect the X3 harness connector at the appropriate seat memory control module listed below:

  • K40D Seat Memory Control Module - Driver
  • K40P Seat Memory Control Module - Passenger

2. Test for infinite resistance between each control circuit terminal listed below and ground:

  • Seat front vertical motor up control terminal 3
  • Seat front vertical motor down control terminal 4
  • Seat rear vertical motor up control terminal 5
  • Seat rear vertical motor down control terminal 6
  • Seat horizontal motor forward control terminal 11
  • Seat horizontal motor rearward control terminal 12
  • Seat recline motor forward control terminal 1
  • Seat recline motor rearward control terminal 2
  • If less than infinite resistance

Repair the short to ground on the circuit.

  • Go to next step: If infinite resistance

3. Ignition ON.

4. Test for less than 1 V between each control circuit terminal listed below and ground:

  • Seat front vertical motor up control terminal 3
  • Seat front vertical motor down control terminal 4
  • Seat rear vertical motor up control terminal 5
  • Seat rear vertical motor down control terminal 6
  • Seat horizontal motor forward control terminal 11
  • Seat horizontal motor rearward control terminal 12
  • Seat recline motor forward control terminal 1
  • Seat recline motor rearward control terminal 2
  • If 1 V or greater

Repair the short to voltage on the circuit.

  • Go to next step: If less than 1 V

5. Replace the K40 Seat Memory Control Module.

B3920 00 or B3920 0B

1. Ignition ON.

2. Clear the current and history DTC.

3. Determine which motor set this DTC by operating each seat motor listed below one at a time in both directions. Check for the DTC to set between each motor test.

  • M50 Seat Front Vertical Motor
  • M55 Seat Rear Vertical Motor
  • M51 Seat Horizontal Motor
  • M56 Seat Recline Motor

4. Ignition OFF, disconnect the harness connector at the seat motor for which the DTC set, ignition ON.

5. Clear the DTC.

6. Verify that DTC B3920 00 or B3920 0B does not set while operating the seat motor adjuster switch in both directions.

  • If DTC B3920 00 or B3920 0B sets
  1. Ignition OFF.
  2. Test for infinite resistance between control circuit terminal 1 and control circuit terminal 3.
    • If less than infinite resistance, repair the short between the circuits.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in each control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • Go to next step: If DTC B3920 00 or B3920 0B does not set

7. Test or replace the seat motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Front Seat Tilt Adjuster Actuator Replacement
  • Driver or Passenger Seat Vertical Adjuster Actuator Replacement
  • Driver or Passenger Seat Recliner Actuator Replacement (Except GS) or Driver or Passenger Seat Recliner Actuator Replacement (GS)
  • Control Module References for K40D Seat Memory Control Module - Driver or K40P Seat Memory Control Module - Passenger replacement, programming and setup

DTC B392B

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B392B 00

Seat Lumbar/Bolster Pump

Diagnostic Fault Information

Power Seats

1. The lumbar, bolster and massage functions are inoperative

Circuit/System Description

When a seat lumbar, bolster, or massage function is commanded ON, the seat bolster memory control module applies battery voltage and a low side drive pulse width modulated (PWM) signal through their respective control circuits to the seat lumbar/bolster pump. The logic in the pump interprets this signal and pump runs to inflate the lumbar/bolster bladders until the switch is released.

Conditions for Running the DTC

  • Ignition ON.
  • The voltage control circuit to the lumbar/bolster pump must be active.

Conditions for Setting the DTC

The seat bolster memory control module detects a short to ground on the lumbar/bolster pump voltage control circuit.

Action Taken When the DTC Sets

All lumbar, bolster, and massage functions are inoperative.

Conditions for Clearing the DTC

  • The DTC clears when the diagnostic runs and passes.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Testing

1. Ignition OFF, all vehicle systems OFF, disconnect the harness connector at the appropriate seat lumbar/bolster pump listed below:

  • G31D Seat Lumbar/Bolster Pump - Driver
  • G31P Seat Lumbar/Bolster Pump - Passenger

2. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the low reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K134 Seat Bolster Memory Control Module.
  • Go to next step: If less than 10 Ω

3. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.

4. Verify the test lamp turns ON after pressing and holding the lumbar forward switch.

  • If the test lamp remains OFF
  1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K134 Seat Bolster Memory Control Module.
  2. Test for infinite resistance between the control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K134 Seat Bolster Memory Control Module.
  • Go to next step: If the test lamp turns ON

5. Test or replace the G31 Seat Lumbar/Bolster Pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Front Seat Back Lumbar Replacement (2 Way) or Front Seat Back Lumbar Replacement (GS) or Front Seat Back Lumbar Replacement (4 Way)
  • Control Module References for K134D Seat Bolster Memory Control Module - Driver or K134P Seat Bolster Memory Control Module - Passenger replacement, programming and setup

DTC B392C

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B392C 39

Seat Bolster Memory Control Module Internal Malfunction

Circuit/System Description

The seat memory control module detects an internal electronic fault in the seat bolster memory control module. No external circuits are involved.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

The control module detects an internal fault.

An internal electronic fault in the seat bolster memory control module will set this DTC.

Action Taken When the DTC Sets

All lumbar/bolster functions will be inoperative.

Conditions for Clearing the DTC

  • The DTC clears when the diagnostic runs and passes.
  • The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

Electrical Information Reference

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

DTC B392C

1. Ignition ON.

2. Verify DTC B392C is not set.

  • If the DTC is set

Replace the appropriate K134 Seat Bolster Memory Control Module.

  • Go to next step: If the DTC is not set

3. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for K134D Seat Bolster Memory Control Module - Driver or K134P Seat Bolster Memory Control Module - Passenger replacement, programming and setup.

Symptoms - Power Seats

NOTE: The following steps must be completed before using the symptom tables.

1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following are true:

  • There are no DTCs set.
  • The control modules can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following system descriptions:

  • Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)
  • Memory Seats Description and Operation
  • Power Seats System Description and Operation

Visual/Physical Inspection

  • Inspect for aftermarket devices which could affect the operation of the system. Refer to Checking Aftermarket Accessories.
  • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

  • Lumbar/Bolster/Massage Malfunction (AVK with AF6 or AVU with AKE), Lumbar/Bolster/Massage Malfunction (AVK without AF6 or AVU without AKE), or Lumbar/Bolster/Massage Malfunction (AL9 or AT9)
  • Memory Seat Feature Malfunction
  • Power Seat Malfunction (Driver or Passenger without Memory A44 or A45), Power Seat Malfunction (Driver Seat with Memory A45), or Power Seat Malfunction (Passenger Seat with Memory A44)
  • Power Folding Seat Malfunction

Lumbar/Bolster/Massage Malfunction (AVK with AF6 or AVU with AKE)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

1. The lumbar, bolster, and massage functions are inoperative

Circuit/System Description

Ground is supplied to the driver and passenger seat lumbar support and the seat back side bolster switches. Each switch is also supplied with a 5 V reference and signal circuits from the seat memory control module. The reference voltage is applied to a resistive network internal to the switches. When a switch is pressed, the output of the resistive network results in a voltage drop on the signal circuit to the seat memory control module indicating the lumbar, bolster, or massage request. In response to this signal, the seat memory control module sends a LIN serial data message to the seat massage valve assembly commanding it to perform the required pneumatic movements.

The seat massage valve assembly contains the electronic circuitry for executing the commanded pneumatic seat adjustments, air direction solenoids, pressure sensors for storing air bladder pressures, and outputs which supplies battery power and a low side drive pulse width modulated (PWM) signal to the external seat air pump motor when any of the air bladders require inflating.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the appropriate scan tool Driver or Passenger Lumbar Support Horizontal Switch parameter changes between Inactive and Forward/Rearward when pressing the lumbar horizontal switch in the Forward and Rearward directions.

  • If the parameter does not change in either direction

Refer to DTC B183B or B183C.

  • Go to next step: If the parameter changes for both directions

3. Verify the scan tool Lumbar Support Vertical Switch parameter changes between Inactive and Up/Down when pressing the lumbar vertical switch in the Up and Down directions.

  • If the parameter does not change

Test or replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If the parameter changes

4. Verify the scan tool Seat Back Side Bolster Switch parameter changes between Inactive and Inflate/Deflate when pressing the bolster switch in both directions.

  • If the parameter does not change

Refer to DTC B183B or B183C.

  • Go to next step: If the parameter changes

5. Verify the scan tool Seat Massage Switch parameter changes between Inactive and Active when pressing the seat massage switch.

  • If the parameter does not change

Test or replace the S66 Seat Back Side Bolster Adjuster Switch.

  • Go to next step: If the parameter changes

6. Refer to Circuit/System Testing.

Circuit/System Testing

1. Ignition OFF, all vehicle systems OFF, disconnect the harness connector at the appropriate seat bolster memory control module listed below. It may take up to 2 min for all vehicle systems to power down.

  • K134D Seat Bolster Memory Control Module - Driver
  • K134P Seat Bolster Memory Control Module - Passenger

2. Test for less than 10 Ω between the ground circuit terminal 3 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.

  • If the test lamp does not illuminate
  1. Ignition OFF, remove the test lamp.
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates

5. Ignition OFF, connect the harness connector at the K134 Seat Bolster Memory Control Module and disconnect the harness connector at the G31 Seat Lumbar/Bolster Pump.

6. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the low reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, replace the K134 Seat Bolster Memory Control Module.
  • Go to next step: If less than 10 Ω

7. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.

8. Verify the test lamp turns ON when pressing the lumbar forward switch.

  • If the test lamp remains OFF
  1. Ignition OFF, remove the teat lamp, disconnect the harness connector at the K134 Seat Bolster Memory Control Module.
  2. Test for infinite resistance between the control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, replace the K134 Seat Bolster Memory Control Module.
  • If the test lamp remains ON
  1. Ignition OFF, remove the teat lamp, disconnect the harness connector at the K134 Seat Bolster Memory Control Module, ignition ON.
  2. Test for less than 1 V between the control circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K134 Seat Bolster Memory Control Module.
  • Go to next step: If the test lamp turns ON and OFF

9. Test or replace the G31 Seat Lumbar/Bolster Pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Lumbar Control Switch Replacement
  • Front Seat Back Lumbar Replacement (2 Way) or Front Seat Back Lumbar Replacement (GS) or Front Seat Back Lumbar Replacement (4 Way)

Lumbar/Bolster/Massage Malfunction (AVK without AF6 or AVU without AKE)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

1. The seat lumbar support functions are inoperative
2. The seat lumbar support pump is always ON

Circuit/System Description

The seat lumbar support valve assembly supplies the seat lumbar support switch with a signal and low reference circuits. When a lumbar switch is pressed, the signal circuit from the seat lumbar support valve assembly is pulled low through the switch contacts and series of resistors indicating the lumbar support request. In response to this request, the lumbar adjuster valve assembly energizes its internal inflate solenoid and applies battery voltage through the lumbar support pump control circuit to the pump. The pump runs to inflate the appropriate support bladder until the switch is released.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate seat lumbar support valve assembly listed below. It may take up to 2 min for all vehicle systems to power down.

  • Q51D Seat Lumbar Support Valve Assembly - Driver
  • Q51P Seat Lumbar Support Valve Assembly - Passenger

2. Test for less than 10 Ω between the ground circuit terminal 2 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.

  • If the test lamp does not illuminate
  1. Ignition OFF, remove the test lamp.
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates

5. Ignition OFF and all vehicle systems OFF, connect the harness connector at the Q51 Seat Lumbar Support Valve Assembly and disconnect the harness connector at the S65 Seat Lumbar Support Switch. It may take up to 2 min for all vehicle systems to power down.

6. Test for less than 10 Ω between the low reference circuit terminal 1 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the low reference circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, test or replace the Q51 Seat Lumbar Support Valve Assembly.
  • Go to next step: If less than 10 Ω

7. Ignition ON.

8. Test for 4.8 - 5.2 V between the signal circuit terminal 2 and ground.

  • If less than 4.8 V
  1. Ignition OFF, disconnect the harness connector at the Q51 Seat Lumbar Support Valve Assembly.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, test or replace the Q51 Seat Lumbar Support Valve Assembly.
  • If greater than 5.2 V
  1. Ignition OFF, disconnect the harness connector at the Q51 Seat Lumbar Support Valve Assembly, ignition ON.
  2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, test or replace the Q51 Seat Lumbar Support Valve Assembly.
  • Go to next step: If between 4.8 - 5.2 V

9. Ignition OFF, connect the harness connector at the S65 Seat Lumbar Support Switch and disconnect the harness connector at the Q51 Seat Lumbar Support Valve Assembly.

10. Connect a DDM between the signal circuit terminal 4 and the low reference circuit terminal 5.

11. Test for the resistance values listed below while pressing the appropriate S65 Seat Lumbar Support Switch.

  • 146 - 178 Ω for the lumbar forward switch
  • 459 - 561 Ω for the lumbar rearward switch
  • 1134 - 1386 Ω for the lumbar down switch
  • 3024 - 3696 Ω for the lumbar up switch
  • If not between the specified values

Test or replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between the specified values

12. Ignition OFF, connect the harness connector at the Q51 Seat Lumbar Support Valve Assembly and disconnect the harness connector at the G31 Seat Lumbar/Bolster Pump.

13. Test for less than 10 Ω between the ground circuit terminal 2 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

14. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.

15. Verify the test lamp turns ON and OFF when pressing and releasing the lumbar forward switch.

  • If the test lamp remains OFF
  1. Ignition OFF, remove the test lamp, disconnect the harness connector at the Q51 Seat Lumbar Support Valve Assembly.
  2. Test for infinite resistance between the control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, test or replace the Q51 Seat Lumbar Support Valve Assembly.
  • If the test lamp is always ON
  1. Ignition OFF, remove the teat lamp, disconnect the harness connector at the Q51 Seat Lumbar Support Valve Assembly, ignition ON.
  2. Test for less than 1 V between the control circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the Q51 Seat Lumbar Support Valve Assembly.
  • Go to next step: If the test lamp turns ON and OFF

16. Test or replace the G31 Seat Lumbar/Bolster Pump.

Component Testing

Seat Lumbar Support Switch

1. Ignition OFF, disconnect the harness connector at the appropriate S65 Seat Lumbar Support Switch.

2. Test for infinite resistance between the signal terminal 2 and the low reference terminal 1 with the switch in the open position.

  • If less than infinite resistance

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If infinite resistance

3. Test for 146 - 178 Ω between the signal terminal 2 and the low reference terminal 1 while pressing the lumbar forward switch.

  • If not between 146 - 178 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 146 - 178 Ω

4. Test for 459 - 561 Ω between the signal terminal 2 and the low reference terminal 1 while pressing the lumbar rearward switch.

  • If not between 459 - 561 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 459 - 561 Ω

5. Test for 1134 - 1386 Ω between the signal terminal 2 and the low reference terminal 1 while pressing the lumbar down switch.

  • If not between 1134 - 1386 Ω

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 1134 - 1386 Ω

6. Test for 3.02k - 3.7 kΩ between the signal terminal 2 and the low reference terminal 1 while pressing the lumbar up switch.

  • If not between 3.02k - 3.7 kΩ

Replace the S65 Seat Lumbar Support Switch.

  • Go to next step: If between 3.02k - 3.7 kΩ

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Lumbar Control Switch Replacement
  • Front Seat Back Lumbar Replacement (2 Way) or Front Seat Back Lumbar Replacement (GS) or Front Seat Back Lumbar Replacement (4 Way)

Lumbar/Bolster/Massage Malfunction (AL9 or AT9)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

1. The power seat and the lumbar support functions are inoperative
2. The lumbar support is inoperative

Circuit/System Description

Battery voltage is supplied at all times to the seat adjuster switch through a 10 A fuse located in the underhood fuse block. When a lumbar switch is pressed to inflate the lumbar support, battery voltage is applied through the switch contacts and the inflate control circuit to the seat lumbar support valve assembly. In response to this signal, the valve assembly energizes its internal inflate solenoid and runs to inflate the lumbar bladder until the switch is released. When the switch is pressed to deflate the lumbar support, battery voltage is applied through the switch contacts and the deflate signal circuit to the seat lumbar support valve assembly. The valve assembly energizes its internal deflate solenoid and air is released from the bladder until the switch is released.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Circuit/System Verification

1. Ignition ON.

2. Verify the seat lumbar operates in both directions - Forward/Rearward.

  • If either seat lumbar function does not operate

Refer to Circuit/System Testing

  • Go to next step: If both seat lumbar functions operate

3. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate seat lumbar support switch listed below. It may take up to 2 min for all vehicle systems to power down.

  • S65D Seat Lumbar Support Switch - Driver
  • S65P Seat Lumbar Support Switch - Passenger

2. Test for less than 10 Ω between the ground circuit terminal E and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal G and ground.

  • If the test lamp does not illuminate
  1. Ignition OFF.
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the circuit fuse is OK and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates

5. Ignition OFF, connect the harness connector at the S65 Seat Lumbar Support Switch and disconnect the harness connector at the Q51 Seat Lumbar Support Valve Assembly.

6. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2, ignition ON.

7. Verify the test lamp turns ON when pressing the lumbar switch in the Forward and Rearward directions.

  • If the test lamp remains OFF during either of the commands
  1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S65 Seat Lumbar Support Switch.
  2. Test for infinite resistance between each control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in each control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, test or replace the S65 Seat Lumbar Support Switch.
  • Go to next step: If the test lamp turns ON during each of the commands

8. Test or replace the Q51 Seat Lumbar Support Valve Assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Adjuster Switch Replacement
  • Front Seat Back Lumbar Replacement (2 Way) or Front Seat Back Lumbar Replacement (GS) or Front Seat Back Lumbar Replacement (4 Way)

Memory Seat Feature Malfunction

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

1. Memory seat feature is inoperative

Circuit/System Description

Low reference is supplied to the seat memory switch from the seat memory control module. When a memory switch is pressed, the signal circuit from the seat memory control module is pulled low through the switch contacts and series of resistors indicating the memory recall request. In response to this signal, the seat memory control module commands the appropriate seat motors to move to the prerecorded seat positions stored in memory.

Diagnostic Aids

  • The seat memory control module must be awake when measuring voltage from either one of the memory seat switch signal circuits. Voltage readings of 0.0 V or 5.0 V are possible if the module is not fully awake and result in misdiagnosing the circuit.
  • When using remote keyless entry for vehicle access, the driver seat memory functions will operate only with transmitters 1 and 2. Transmitters 3 - 8 cannot be programmed for memory seat functions.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify that all manual power seat functions operate when being controlled by the power seat adjuster switches.

  • If any manual power seat function does not operate

Refer to Power Seat Malfunction (Driver or Passenger without Memory A44 or A45), Power Seat Malfunction (Driver Seat with Memory A45), or Power Seat Malfunction (Passenger Seat with Memory A44)

  • Go to next step: If all manual power seat functions operate

3. Refer to Circuit/System Testing.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate seat memory switch listed below:

  • S47D Seat Memory Switch - Driver
  • S47P Seat Memory Switch - Passenger

2. Test for less than 30 Ω between the low reference circuit terminal 1 and ground.

  • If 30 Ω or greater
  1. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module.
  2. Test for less than 2 Ω in the low reference circuit end to end
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • Go to next step: If less than 30 Ω

3. Ignition ON, press a power seat switch in order to wake up the K40 Seat Memory Control Module.

4. Test for 9 V or greater between each signal circuit terminal listed below and ground:

  • Memory set switch signal terminal 5
  • Memory switch signal terminal 6
  • If less than 9 V
  1. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module.
  2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40 Seat Memory Control Module.
  • Go to next step: If 9 V or greater

5. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module, ignition ON.

6. Test for less than 1 V between each signal circuit terminal listed below and ground:

  • Memory set switch signal terminal 5
  • Memory switch signal terminal 6
  • If 1 V or greater

Repair the short to voltage on the circuit.

  • Go to next step: If less than 1 V

7. Test or replace the S47 Seat Memory Switch.

Component Testing

Seat Memory Switch

1. Ignition OFF, disconnect the harness connector at the S47 Seat Memory Switch.

2. Test for infinite resistance between each signal terminal listed below and the low reference terminal 1 with the switch in the open position.

  • Terminal 5
  • Terminal 6
  • If less than infinite resistance

Replace the S47 Seat Memory Switch.

  • Go to next step: If infinite resistance

3. Test for less than 4 Ω between the signal terminal 5 and the low reference terminal 1 while pressing the memory SET button.

  • If 4 Ω or greater

Replace the S47 Seat Memory Switch.

  • Go to next step: If less than 4 Ω

4. Test for 573 - 701 Ω between the signal terminal 6 and the low reference terminal 1 while pressing the memory 1 button.

  • If not between 573 - 701 Ω

Replace the S47 Seat Memory Switch.

  • Go to next step: If between 573 - 701 Ω

5. Test for 1800 - 2201 Ω between the signal terminal 6 and the low reference terminal 1 while pressing the memory 2 button.

  • If not between 1800 - 2201 Ω

Replace the S47 Seat Memory Switch.

  • Go to next step: If between 1800 - 2201 Ω

6. Test for 5.52k - 6.73 kΩ between the signal terminal 6 and the low reference terminal 1 while pressing the Exit button.

  • If not between 5.52k - 6.73 kΩ

Replace the S47 Seat Memory Switch.

  • Go to next step: If between 5.52k - 6.73 kΩ

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Front Seat Adjuster Memory Switch Replacement
  • Control Module References for K40D Seat Memory Control Module - Driver or K40P Seat Memory Control Module - Passenger replacement, programming and setup

Power Folding Seat Malfunction

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

1. The left rear power folding seat is inoperative.
2. The right rear power folding seat is inoperative.

Circuit/System Description

Battery voltage is supplied at all times to the folding seat control switch through a 15 A fuse located in the instrument panel fuse block. When the folding seat control switch is pressed to fold the seat back cushion forward, battery voltage is applied through the switch contacts and the folding seat motor control circuit to the motor. The motor runs in order to fold the seat back cushion forward.

Reference Information

Schematic Reference

Rear Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Power Seats System Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate folding seat motor listed below:

  • M19LR Folding Seat Motor - Left Rear
  • M19RR Folding Seat Motor - Right Rear

2. Test for less than 10 Ω between the ground circuit terminal and ground.

  • If 10 Ω or greater
  1. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Connect a test lamp between the control circuit terminal 1 and the ground circuit terminal 2, ignition ON.

4. Verify the test lamp does not turn ON when commanding the M19 Folding Seat Motor froward using the S20 Folding Seat Control Switch.

  • If the test lamp turns ON during each of the commands

5. Test or replace the M19 Folding Seat Motor.

  • Go to next step: If the test lamp does not turn ON during either of the commands

6. Ignition OFF, disconnect the harness connector at the appropriate folding seat control switch listed below:

  • S20LR Folding Seat Control Switch - Left Rear
  • S20RR Folding Seat Control Switch - Right Rear

7. Ignition ON.

8. Verify a test lamp illuminates between the B+ circuit terminal 5 and ground.

  • If the test lamp does not illuminate
  1. Ignition OFF.
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates

9. Test for infinite resistance between the control circuit and ground.

  • If less than infinite resistance, repair the short to ground on the circuit.
  • Go to next step: If infinite resistance

10. Test for less than 2 Ω in the control circuit end to end.

  • If 2 Ω or greater, repair the open/high resistance in the circuit.
  • Go to next step: If less than 2 Ω

11. Test or replace the S20 Folding Seat Control Switch.

Component Testing

Folding Seat Control Switch

1. Ignition OFF, disconnect the harness connector at the S20 Folding Seat Control Switch.

2. Test for infinite resistance between the B+ terminal 5 and the control terminal 1 with the switch in the open position.

  • If less than infinite resistance

Replace the S20 Folding Seat Control Switch.

3. Test for less than 2 Ω between the B+ terminal 5 and each control terminal 1 with the switch in the closed position.

  • If 2 Ω or greater

Replace the S20 Folding Seat Control Switch.

  • Go to next step: If less than 2 Ω

4. All OK.

Folding Seat Motor

1. Ignition OFF, disconnect the harness connector at the M19 Folding Seat Motor.

NOTE: When performing the following tests, make sure that the seat is not already in the position the test is attempting to produce.

2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.

3. Momentarily install a jumper wire between control terminal 2 and ground. The seat motor should momentarily perform the FORWARD function.

  • If the motor does not perform the FORWARD function

Replace the motor.

  • Go to next step: If the motor performs the FORWARD function

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Rear Seat Back Folding Switch Replacement
  • Rear Seat Recliner Actuator Replacement

Power Seat Malfunction (Driver or Passenger without Memory A44 or A45)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

1. All power seat motors are inoperative
2. The seat front vertical motor is inoperative
3. The seat horizontal motor is inoperative
4. The seat rear vertical motor is inoperative
5. The seat recline motor is inoperative
6. The seat motor operates until maximum travel is reached

Circuit/System Description

The driver and passenger power seats are completely controlled through the seat adjuster switch. Battery voltage is supplied at all times to the seat adjuster switch through a 30 A fuse located in the underhood fuse block. When the seat switches are in an inactive state, the switch contacts are closed to the switch ground circuit.

All seat motors are reversible. For example, when the seat horizontal forward switch is pressed to move the entire seat forward, battery voltage is applied through the switch contacts and the seat horizontal motor rearward control circuit to the motor. With the horizontal motor rearward switch contacts closed to the switch ground circuit, the motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. All seat motors are powered this way.

Reference Information

Schematic Reference

  • Driver Seat Wiring Schematics
  • Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Power Seats System Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Circuit/System Verification

1. Verify the appropriate driver or passenger seat directional motors listed below operate while operating the seat switches in both directions.

  • M51 Seat Horizontal Motor
  • M50 Seat Front Vertical Motor
  • M55 Seat Rear Vertical Motor
  • M56 Seat Recline Motor
  • If all seat motors do not operate

Refer to Circuit/System Testing - Seat Adjuster Switch Circuit Test.

  • If 1 or more seat motors operate

Refer to Circuit/System Testing - Seat Motor Circuit Test.

  • Go to next step: If all seat motors operate

2. All OK.

Circuit/System Testing

Seat Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat adjuster switch listed below:

  • S64D Seat Adjuster Switch - Driver
  • S64P Seat Adjuster Switch - Passenger

2. Test for less than 10 Ω between the ground circuit terminal B and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal E and ground.

  • If the test lamp does not illuminate
  1. Ignition OFF
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the circuit fuse is OK and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates

5. Test or replace the S64 Seat Adjuster Switch.

Seat Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below:

  • M51 Seat Horizontal Motor
  • M50 Seat Front Vertical Motor
  • M55 Seat Rear Vertical Motor
  • M56 Seat Recline Motor

2. Ignition on.

3. Test for less than 1 V between each control circuit and ground.

  • If 1 V or greater, repair short to voltage in the control circuit.
  • Go to next step: If less than 1 V.

4. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3, ignition ON.

5. Verify the test lamp turns ON when commanding the seat motor Up and Down or Forward and Rearward using the seat adjuster switch.

  • If the test lamp remains OFF during either of the commands
  1. Ignition OFF, disconnect the harness connector at the S64 Seat Adjuster Switch.
  2. Test for infinite resistance between each control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in each control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, test or replace the S64 Seat Adjuster Switch.
  • Go to next step: If the test lamp turns ON during each of the commands

6. Test or replace the seat motor.

Component Testing

Seat Adjuster Switch Test

1. Ignition OFF, disconnect the harness connector at the S64 Seat Adjuster Switch.

2. Test for infinite resistance between the B+ terminal E and each control terminal with the switch in the open position.

  • If less than infinite resistance

Replace the S64 Seat Adjuster Switch.

  • Go to next step: If infinite resistance

3. Test for less than 2 Ω between the B+ terminal E and each control terminal with the appropriate switch in the closed position.

  • If 2 Ω or greater

Replace the S64 Seat Adjuster Switch.

  • Go to next step: If less than 2 Ω

4. Test for less than 2 Ω between the ground terminal B and each control terminal with the switch in the open position.

  • If 2 Ω or greater

Replace the S64 Seat Adjuster Switch.

  • Go to next step: If less than 2 Ω

5. All OK.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below:

  • M51 Seat Horizontal Motor
  • M50 Seat Front Vertical Motor
  • M55 Seat Rear Vertical Motor
  • M56 Seat Recline Motor

NOTE: When performing the following tests, make sure that the seat is not already in the position the test is attempting to produce.

2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.

3. Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD/ REARWARD/ UP/ DOWN function.

  • If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the motor.

  • Go to next step: If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

4. Reverse the jumper wires; the motor should perform FORWARD/ REARWARD/ UP/ DOWN function.

  • If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the motor.

  • Go to next step: If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  • Driver or Passenger Seat Adjuster Switch Replacement
  • Front Seat Tilt Adjuster Actuator Replacement
  • Driver or Passenger Seat Vertical Adjuster Actuator Replacement
  • Driver or Passenger Seat Recliner Actuator Replacement (Except GS) or Driver or Passenger Seat Recliner Actuator Replacement (GS)

Power Seat Malfunction (Driver Seat with Memory A45)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

Power Seats

Power Seats

1. All power seat motors are inoperative
2. The seat front vertical motor is inoperative
3. The seat horizontal motor is inoperative
4. The seat rear vertical motor is inoperative
5. The seat recline motor is inoperative

Circuit/System Description

Battery voltage is supplied at all times to the seat memory control module through a 5 A fuse located in the underhood fuse block. This voltage is used by the module for logic power. Battery positive voltage is also supplied at all times to the seat memory control module through a 30 A fuse also located in the underhood fuse block. This voltage is connected to a power rail internal to the seat memory control module and is used to drive all driver power seat motors. Each seat motor is controlled by the seat memory control module by applying power and ground through the control circuits to the motor.

All motors are reversible. For example, when the seat switch is operated to move the entire seat forward, the switch signal circuit from the seat memory control module is pulled low indicating the entire seat forward command. In response to this signal, the seat memory control module applies battery voltage through the driver seat horizontal motor forward control circuit and ground through the driver seat horizontal motor rearward control circuit to the motor. The motor runs to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. All driver power seat motors are powered this way.

Reference Information

Schematic Reference

Driver Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the scan tool seat switch parameters listed below change between Inactive and Forward/Rearward or Up/Down when pressing the appropriate switch.

  • Driver Seat Horizontal Switch
  • Driver Seat Cushion Front Vertical Switch
  • Driver Seat Cushion Rear Vertical Switch
  • Driver Seat Back Switch
  • If any parameter does not change

Refer to Circuit/System Testing - Seat Adjuster Switch Circuit Test

  • Go to next step: If all parameters change

3. Verify the seat directional motors listed below operate when pressing the appropriate seat switches in both directions.

  • M50D Seat Front Vertical Motor - Driver
  • M55D Seat Rear Vertical Motor - Driver
  • M51D Seat Horizontal Motor - Driver
  • M56D Seat Recline Motor - Driver
  • If any seat motor does not operate

Refer to Circuit/System Testing - Seat Motor Control Circuit Test.

  • Go to next step: If all seat motors operate

4. All OK.

Circuit/System Testing

Seat Adjuster Switch Circuit Test

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S64D Seat Adjuster Switch - Driver. It may take up to 2 min for all vehicle systems to power down.

2. Test for less than 10 Ω between the ground circuit terminal E and ground.

  • If 10 Ω or greater
  1. Ignition Off.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Install a 3 A fused jumper wire between the ground circuit terminal E and the appropriate signal circuit terminal listed below, ignition ON.

  • Front vertical up switch terminal A
  • Front vertical down switch terminal K
  • Rear vertical up switch terminal F
  • Rear vertical down switch terminal J
  • Horizontal forward switch terminal D
  • Horizontal rearward switch terminal C
  • Recline forward switch terminal H
  • Recline rearward switch terminal G

4. Verify the appropriate scan tool seat switch parameter is Forward/Rearward or UP/Down.

  • If not Forward/Rearward or UP/Down
  1. Ignition OFF, disconnect the X5 harness connector at the K40D Seat Memory Control Module - Driver, ignition ON.
  2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V
  3. Ignition OFF.
  4. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40D Seat Memory Control Module - Driver.
  • Go to next step: If Forward/Rearward or UP/Down

5. Test or replace the S64D Seat Adjuster Switch - Driver.

Seat Motor Control Circuit Test

1. Ignition OFF, disconnect the X2 harness connector at the K40D Seat Memory Control Module - Driver.

2. Test for less than 10 Ω between ground circuit terminal 5 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition OFF, disconnect the X1 harness connector at the K40D Seat Memory Control Module - Driver, ignition ON.

4. Verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

  • If the test lamp does not illuminate.
  1. Ignition OFF, remove the test lamp.
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the shot to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates.

5. Ignition OFF, connect the X1 and X2 harness connectors at the K40D Seat Memory Control Module - Driver and disconnect the harness connector at the appropriate seat motor listed below:

  • M50D Seat Front Vertical Motor - Driver
  • M55D Seat Rear Vertical Motor - Driver
  • M51D Seat Horizontal Motor - Driver
  • M56D Seat Recline Motor - Driver

6. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3, ignition ON.

NOTE: Once a seat motor is commanded On using the scan tool, the seat function may not work using the seat adjuster switch until you back out of the scan tool Control Functions menu.

7. Verify the test lamp turns ON when commanding the seat motor in the Up/Down or Forward/Rearward states with a scan tool.

  • If the test lamp remains OFF during either of the commands
  1. Ignition OFF, disconnect the X3 harness connector at the K40D Seat Memory Control Module - Driver.
  2. Test for infinite resistance between each control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in each control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40D Seat Memory Control Module - Driver.
  • Go to next step: If the test lamp turns ON during each of the commands

8. Test or replace the seat motor.

Component Testing

Seat Adjuster Switch Test

1. Ignition OFF, disconnect the harness connector at the S64D Seat Adjuster Switch - Driver.

2. Test for infinite resistance between the ground terminal E and each signal terminal with the switch in the open position.

  • If less than infinite resistance

Replace the S64D Seat Adjuster Switch - Driver.

  • Go to next step: If infinite resistance

3. Test for less than 2 Ω between the ground terminal E and each signal terminal with the appropriate switch in the closed position.

  • If 2 Ω or greater

Replace the S64D Seat Adjuster Switch - Driver.

  • Go to next step: If less than 2 Ω

4. All OK.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below:

  • M50D Seat Front Vertical Motor - Driver
  • M55D Seat Rear Vertical Motor - Driver
  • M51D Seat Horizontal Motor - Driver
  • M56D Seat Recline Motor - Driver

NOTE: When performing the following tests, make sure that the seat is not already in the position the test is attempting to produce.

2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.

3. Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD/ REARWARD/ UP/ DOWN function.

  • If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the seat motor.

  • Go to next step: If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

4. Reverse the jumper wires; the motor should perform FORWARD/ REARWARD/ UP/ DOWN function.

  • If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the seat motor.

  • Go to next step: If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Adjuster Switch Replacement
  • Front Seat Tilt Adjuster Actuator Replacement
  • Driver or Passenger Seat Vertical Adjuster Actuator Replacement
  • Driver or Passenger Seat Recliner Actuator Replacement (Except GS) or Driver or Passenger Seat Recliner Actuator Replacement (GS)
  • Control Module References for K40D Seat Memory Control Module - Driver replacement, programming and setup

Power Seat Malfunction (Passenger Seat with Memory A44)

Diagnostic Instructions

  • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Power Seats

Power Seats

Power Seats

1. All power seat motors are inoperative
2. The seat front vertical motor is inoperative
3. The seat horizontal motor is inoperative
4. The seat rear vertical motor is inoperative
5. The seat recline motor is inoperative

Circuit/System Description

Battery voltage is supplied at all times to the seat memory control module through a 5 A fuse located in the underhood fuse block. This voltage is used by the module for logic power. Battery positive voltage is also supplied at all times to the seat memory control module through a 30 A fuse also located in the underhood fuse block. This voltage is connected to a power rail internal to the seat memory control module and is used to drive all power seat motors. Each seat motor is controlled by the seat memory control module by applying power and ground through the control circuits to the motor.

All motors are reversible. For example, when the seat switch is operated to move the entire seat forward, the switch signal circuit from the seat memory control module is pulled low indicating the entire seat forward command. In response to this signal, the seat memory control module applies battery voltage through the seat horizontal motor forward control circuit and ground through the seat horizontal motor rearward control circuit to the motor. The motor runs to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. All power seat motors are powered this way.

Reference Information

Schematic Reference

Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

  • Circuit Testing
  • Connector Repairs
  • Testing for Intermittent Conditions and Poor Connections
  • Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the scan tool seat switch parameters listed below change between Inactive and Forward/Rearward or Up/Down when pressing the appropriate switch.

  • Passenger Seat Horizontal Switch
  • Passenger Seat Cushion Front Vertical Switch
  • Passenger Seat Cushion Rear Vertical Switch
  • Passenger Seat Back Switch
  • If any parameter does not change

Refer to Circuit/System Testing - Seat Adjuster Switch Circuit Test

  • Go to next step: If all parameters change

3. Verify the seat directional motors listed below operate when pressing the appropriate seat switches in both directions.

  • M50P Seat Front Vertical Motor - Passenger
  • M55P Seat Rear Vertical Motor - Passenger
  • M51P Seat Horizontal Motor - Passenger
  • M56P Seat Recline Motor - Passenger
  • If any seat motor does not operate

Refer to Circuit/System Testing - Seat Motor Control Circuit Test.

  • Go to next step: If all seat motors operate

4. All OK.

Circuit/System Testing

Seat Adjuster Switch Circuit Test

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S64P Seat Adjuster Switch - Passenger. It may take up to 2 min for all vehicle systems to power down.

2. Test for less than 10 Ω between the ground circuit terminal E and ground.

  • If 10 Ω or greater
  1. Ignition Off.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Install a 3 A fused jumper wire between the ground circuit terminal E and the appropriate signal circuit terminal listed below, ignition ON.

  • Front vertical up switch terminal K
  • Front vertical down switch terminal A
  • Rear vertical up switch terminal J
  • Rear vertical down switch terminal F
  • Horizontal forward switch terminal D
  • Horizontal rearward switch terminal C
  • Recline forward switch terminal H
  • Recline rearward switch terminal G

4. Verify the appropriate scan tool seat switch parameter is Forward/Rearward or UP/Down.

  • If not Forward/Rearward or UP/Down
  1. Ignition OFF, disconnect the X5 harness connector at the K40P Seat Memory Control Module - Passenger, ignition ON.
  2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V
  3. Ignition OFF.
  4. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40P Seat Memory Control Module - Passenger.
  • Go to next step: If Forward/Rearward or UP/Down

5. Test or replace the S64P Seat Adjuster Switch - Passenger.

Seat Motor Control Circuit Test

1. Ignition OFF, disconnect the X2 harness connector at the K40P Seat Memory Control Module - Passenger.

2. Test for less than 10 Ω between ground circuit terminal 5 and ground.

  • If 10 Ω or greater
  1. Ignition OFF.
  2. Test for less than 2 Ω in the ground circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, repair the open/high resistance in the ground connection.
  • Go to next step: If less than 10 Ω

3. Ignition OFF, disconnect the X1 harness connector at the K40P Seat Memory Control Module - Passenger, ignition ON.

4. Verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

  • If the test lamp does not illuminate.
  1. Ignition OFF, remove the test lamp.
  2. Test for infinite resistance between the B+ circuit and ground.
    • If less than infinite resistance, repair the shot to ground on the circuit.
    • Go to next step: If infinite resistance.
  3. Test for less than 2 Ω in the B+ circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse.
  • Go to next step: If the test lamp illuminates.

5. Ignition OFF, connect the X1 and X2 harness connectors at the K40P Seat Memory Control Module - Passenger and disconnect the harness connector at the appropriate seat motor listed below:

  • M50P Seat Front Vertical Motor - Passenger
  • M55P Seat Rear Vertical Motor - Passenger
  • M51P Seat Horizontal Motor - Passenger
  • M56P Seat Recline Motor - Passenger

6. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3, ignition ON.

NOTE: Once a seat motor is commanded On using the scan tool, the seat function may not work using the seat adjuster switch until you back out of the scan tool Control Functions menu.

7. Verify the test lamp turns ON when commanding the seat motor in the Up/Down or Forward/Rearward states with a scan tool.

  • If the test lamp remains OFF during either of the commands
  1. Ignition OFF, disconnect the X3 harness connector at the K40P Seat Memory Control Module - Passenger.
  2. Test for infinite resistance between each control circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If infinite resistance
  3. Test for less than 2 Ω in each control circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K40P Seat Memory Control Module - Passenger.
  • Go to next step: If the test lamp turns ON during each of the commands

8. Test or replace the seat motor.

Component Testing

Seat Adjuster Switch Test

1. Ignition OFF, disconnect the harness connector at the S64P Seat Adjuster Switch - Passenger.

2. Test for infinite resistance between the ground terminal E and each signal terminal with the switch in the open position.

  • If less than infinite resistance

Replace the S64P Seat Adjuster Switch - Passenger.

  • Go to next step: If infinite resistance

3. Test for less than 2 Ω between the ground terminal E and each signal terminal with the appropriate switch in the closed position.

  • If 2 Ω or greater

Replace the S64P Seat Adjuster Switch - Passenger.

  • Go to next step: If less than 2 Ω

4. All OK.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below:

  • M50P Seat Front Vertical Motor - Passenger
  • M55P Seat Rear Vertical Motor - Passenger
  • M51P Seat Horizontal Motor - Passenger
  • M56P Seat Recline Motor - Passenger

NOTE: When performing the following tests, make sure that the seat is not already in the position the test is attempting to produce.

2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.

3. Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD/ REARWARD/ UP/ DOWN function.

  • If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the seat motor.

  • Go to next step: If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

4. Reverse the jumper wires; the motor should perform FORWARD/ REARWARD/ UP/ DOWN function.

  • If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the seat motor.

  • Go to next step: If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  • Driver or Passenger Seat Adjuster Switch Replacement
  • Front Seat Tilt Adjuster Actuator Replacement
  • Driver or Passenger Seat Vertical Adjuster Actuator Replacement
  • Driver or Passenger Seat Recliner Actuator Replacement (Except GS) or Driver or Passenger Seat Recliner Actuator Replacement (GS)
  • Control Module References for K40P Seat Memory Control Module - Passenger replacement, programming and setup

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