Power Seat System Cadillac CTS II

Fastener Tightening Specifications

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The memory seat module (MSM) monitors the current supplied to the driver seat adjuster motors, recline motor and the lumbar motors. It can detect both absolute and differential current levels from the seat motors. Absolute current is the maximum allowable current the module will supply to the motors. A differential current mismatch occurs when the current supplied to the seat motors does not match the current returning from the motors.

Conditions for Running the DTC

The seat adjuster motors, recline motor or the lumbar motor must be active.

B1335 0B

The absolute current or an over-current has exceeded the maximum value allowed.

B1335 42

This DTC will set if the module calibration is not programmed.

B1335 4B

This DTC will set if the module calibration is out of range.

Action Taken When the DTC Sets

All movement related to the seat cushion motors, recline and driver seat lumbar motors is aborted.

Conditions for Clearing the DTC

1. The current DTC will clear and set the code to history, 3 seconds after no motor movement is requested or the current is no longer mismatched, and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, use a scan tool to clear the current and history diagnostic trouble code.
2. Determine which motor set this DTC by operating the motors listed below one at a time in both directions. Check for the DTC to set between each motor test. Driver seat front vertical motor Driver seat rear vertical motor Driver seat horizontal motor Driver seat recline motor Driver seat lumbar horizontal motor
3. Clear the diagnostic trouble codes.
4. Ignition OFF, disconnect the harness connector at the appropriate seat or lumbar motor for which the DTC set.
5. Ignition ON, operate the motor adjuster switch in both directions. DTC B1335 0B should not set. If the DTC sets, test for a short between the appropriate control circuits listed below. If the circuits test normal, replace the MSM. Driver seat front vertical motor terminal 1 and terminal 5 Driver seat rear vertical motor terminal 1 and terminal 5 Driver seat horizontal motor terminal 1 and terminal 5 Driver seat recline motor terminal 1 and terminal 5 Driver seat lumbar horizontal motor terminal A and terminal B
6. Test the appropriate control circuits listed below for a high resistance. If the circuits test normal, test or replace the seat or lumbar motor. Driver seat front vertical motor terminal 1 and terminal 5 Driver seat rear vertical motor terminal 1 and terminal 5 Driver seat horizontal motor terminal 1 and terminal 5 Driver seat recline motor terminal 1 and terminal 5 Driver seat lumbar horizontal motor terminal A and terminal B
7. If all circuits test normal, test or replace the MSM.

B1335 42 or B1335 4B

If either DTC is set, replace the MSM.

Component Testing

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor.
2. Install a 30 A fused jumper wire between the control terminal 1 and 12 volts. Momentarily install a jumper wire between the control terminal 5 and ground. The seat motor should momentarily perform the appropriate FORWARD/REARWARD/UP/DOWN function. If the function does not perform as specified, replace the seat motor.
3. Reverse the polarity of jumper wires. The a seat motor should perform in the opposite direction. If the function does not perform as specified, replace the seat motor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Tilt Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Front Seat Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Driver Seat Outer Adjuster Rear Vertical Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
4. «Seat Lumbar Sub System Replacement (without AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Seat Lumbar Sub System Replacement (with AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
5. «Front Seat Recliner Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
6. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The memory seat module (MSM) monitors the current supplied to both steering column motors. The MSM can detect both absolute and differential current levels from the these motors. Absolute current is the maximum allowable current the module will supply to the motors. A differential current mismatch occurs when the current supplied to the motors does not match the current returning from the motors.

The steering column motors must be active.

B1340 0B

The absolute current has exceeded the maximum value allowed.

B1340 42

This DTC will set if the module calibration is not programmed.

B1340 4B

This DTC will set if the module calibration is not learned.

All movement related to the steering column motors are aborted.

1. The current DTC will clear and set the code to history, 3 seconds after no motor movement is requested or the current is no longer mismatched, and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Diagnostic Aids

The scan tool may reference the Memory Seat Module (MSM) as the Driver Position Module.

Schematic Reference

1. «Driver Seat Schematics»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Tilt/Telescoping Steering Column Schematics»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, use a scan tool to clear the current and history diagnostic trouble code.
2. Determine which motor set this DTC by operating the motors listed below one at a time in both directions. Check for the DTC to set between each motor test. Steering Column Tilt motor Steering Column Telescope motor
3. Clear the diagnostic trouble codes.
4. Ignition OFF, disconnect the harness connector at the appropriate steering column motor for which the DTC set.
5. Ignition ON, operate the motor adjuster switch in both directions. DTC B1340 0B should not set. If the DTC sets, test for a short between the appropriate motor control circuits listed below. If the circuits test normal, replace the MSM. Steering column telescope motor terminal C and terminal D Steering column tilt motor terminal A and terminal B
6. Test the appropriate control circuits listed below for a high resistance. If the circuits test normal, test or replace the steering column. Steering column telescope motor terminal C and terminal D Steering column tilt motor terminal A and terminal B

B1340 42 or B1340 4B

If either DTC is set, replace the MSM.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor.
2. Install a 30 A fused jumper wire between the control terminal 1 and 12 volts. Momentarily install a jumper wire between the control terminal 5 and ground. The seat motor should momentarily perform the appropriate FORWARD/REARWARD/UP/DOWN function. If the function does not perform as specified, replace the seat motor.
3. Reverse the polarity of jumper wires. The a seat motor should perform in the opposite direction. If the function does not perform as specified, replace the seat motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Steering Column Tilt Wheel Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)
2. «Steering Column Telescope Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)
3. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, programming and setup

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The memory seat module (MSM) supplies a 5-volt reference voltage to the driver seat, lumbar, and tilt/telescoping steering column position sensors. The MSM monitors this reference voltage to ensure the accuracy of the voltages being returned from the sensors. If the voltage exceeds the normal operating range, errors will occur in the memory recall operations of the seat and tilt/telescoping steering.

The MSM must be powered.

B1395 02

The reference voltage drops below 4.8 volts for more than 300 mS.

B1395 05

The reference voltage exceeds 5.2 volts for more than 300 mS.

All memory recall functions will be disabled.

1. The current DTC will clear and set the code to history, 3 seconds after the reference voltage returns to the normal operating range and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

1. All position sensors use common ground and 5-volt reference circuits.
2. If the 5-volt reference circuit is shorted to voltage multiple position sensor codes will set.
3. If the 5-volt reference circuit is shorted to ground multiple position sensor codes will set.
4. A short to voltage on one of the position sensor signal circuits may set this DTC.
5. An internal short to ground in one of the position sensors may set this DTC.

Schematic Reference

1. «Driver Seat Schematics»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Tilt/Telescoping Steering Column Schematics»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector for all position sensors connected to the 5-volt reference circuit.
2. Ignition ON, observe all scan tool sensor parameters for Seat 1 and Column Info. The readings should be 0.0 volts. If greater than the specified value, test the appropriate signal circuit listed below for a short to voltage. If the circuit tests normal, replace the MSM. Seat horizontal position sensor terminal B X2 Seat front vertical position sensor terminal B X2 Seat rear vertical position sensor terminal B X2 Recline position sensor terminal 2 Lumbar horizontal position sensor terminal E Steering column telescope position sensor terminal D X2 Steering column tilt position sensor terminal A X2
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit at any one of the position sensors and ground. If less than the specified value, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM. If greater than the specified value, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
4. Connect each position sensor one at a time and verify that the DTC does not set as current. If the DTC sets as current, replace the appropriate position sensor.
5. If all circuits test normal, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Tilt Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Front Seat Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Driver Seat Outer Adjuster Rear Vertical Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
4. «Seat Lumbar Sub System Replacement (without AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Seat Lumbar Sub System Replacement (with AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
5. «Front Seat Recliner Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
6. «Steering Column Tilt Wheel Position Sensor Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)
7. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the power seat switches are pressed, they send a 12 V signal through the switch signal circuits to the memory seat module (MSM). The MSM then commands the driver seat and lumbar motors to move in response to the switch signals.

The MSM must be powered.

Conditions for Setting the DTC

1. If a seat switch circuit is active in one direction and the switch for the opposite direction is pressed, this DTC will set.
2. A short to voltage on a switch signal circuit.

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

1. The current DTC will clear and set the code to history, 3 seconds after the fault is no longer present and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

1. If one of the switch signal circuits is shorted to voltage, multiple codes will set.
2. If a switch is stuck in one direction and the switch is pressed in the opposite direction, a single code will set.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe all scan tool Memory Seat Module seat switch parameters while pressing and releasing each seat directional switch. The readings should change between Inactive and Active.

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Verify all scan tool seat switch parameters listed below are Inactive. Front Vertical Upward Switch Front Vertical Downward Switch Rear Vertical Upward Switch Rear Vertical Downward Switch Horizontal Forward Switch Horizontal Rearward Switch Recline Forward Switch Recline Rearward Switch If not the specified value, test the appropriate signal circuit listed below for a short to voltage. If the circuit tests normal, replace the MSM. Front vertical upward switch terminal A (LHD) Front vertical upward switch terminal K (RHD) Front vertical downward switch terminal K (LHD) Front vertical downward switch terminal A (RHD) Rear vertical upward switch terminal F (LHD) Rear vertical upward switch terminal J (RHD) Rear vertical downward switch terminal J (LHD) Rear vertical downward switch terminal F (RHD) Horizontal forward switch terminal D Horizontal rearward switch terminal C Recline forward switch terminal H Recline rearward switch terminal G
3. If all circuits test normal, test or replace the seat adjuster switch.

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for infinite resistance between the B+ terminal E and each seat direction signal terminal with the switch in the open position. If not the specified value, replace the seat adjuster switch.
3. Test for less than 1 ohms between the B+ terminal E and each seat direction signal terminal with the appropriate switch in the closed position. If greater than the specified value, replace the seat adjuster switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Adjuster Switch Replacement - Driver Side (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Front Seat Adjuster Switch Replacement - Driver Side (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The position sensor that set this diagnostic trouble code (DTC) is either attached to the seat directional motor drive cable or directly to the motor it monitors. It receives a 5 V reference and low reference from the memory seat module (MSM). The sensor sends a voltage signal that varies with the movement of the seat through the signal circuit to the MSM. Then based on this voltage signal, the MSM determines the position of the seat.

The MSM must be powered.

B1825 01, B1850 01, B2355 01, B2365 01, or B2375 01

If the MSM sees the analog input from this sensor is greater than 4.75 V, the sensor will be considered out of range and the MSM will set this DTC.

B1825 06, B1850 06, B2355 06, B2365 06, or B2375 06

If the MSM sees the analog input from this sensor is less than 0.22 V, the sensor will be considered out of range and the MSM will set this DTC.

B1825 5A, B1850 5A, B2355 5A, B2365 5A, or B2375 5A

This DTC will set, if the MSM is controlling a motor in one direction and its position sensor is tracking the motor in the opposite direction. The sensor is either mounted or wired incorrectly, or the polarity of the motor control circuits are reversed.

The MSM disables the memory recall and easy exit/entry action commands of the motor monitored by the sensor. The motor will respond to manual positioning commands.

1. The current DTC will clear and set to history, when the MSM sees the analog input from the sensor as between 0.22 V and 4.75 V and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

1. All position sensors use common ground and 5 V reference circuits.
2. If the 5 V reference circuit is shorted to voltage multiple position sensor codes will set.
3. If the 5 V reference circuit is shorted to ground multiple position sensor codes will set.
4. If the sensor ground circuit is open multiple codes will set.
5. DTC failure type 5 A will set if the sensor setting this DTC is either mounted or wired incorrectly, or the polarity of the motor control circuits are reversed.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

1. «Memory Seats Description and Operation»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system__memory-seats-description-and-operation)
2. «Lumbar Support Description and Operation (Without Memory-A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Lumbar Support Description and Operation (With Memory-A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Memory Seat Module driver seat and lumbar position sensor parameters. The readings should be between 0.22 V and 4.75 V and change while adjusting seat and lumbar positions.

B1825 01 or B1825 06

1. Ignition OFF, disconnect the X2 harness connector at the seat recline motor.
2. Test for less than 2 ohms between the appropriate low reference circuit terminal listed below and ground: Terminal 1 (LHD) Terminal 3 (RHD) If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
3. Ignition ON, test for 4.8 - 5.2 V between the appropriate 5 V reference circuit terminal listed below and ground: Terminal 3 (LHD) Terminal 1 (RHD) If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
4. Verify the scan tool Driver Seat Recline Sensor parameter is less than 1.0 V. If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the MSM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the appropriate 5 V reference circuit terminal listed below. Verify the scan tool Driver Seat Recline Sensor parameter is greater than 4.75 V. Terminal 3 (LHD) Terminal 1 (RHD) If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, test or replace the seat recline position sensor.

B2355 01, B2355 06, B2365 01, B2365 06, B2375 01 or B2375 06

1. Ignition OFF, disconnect the X2 harness connector at the appropriate seat adjuster motor.
2. Test for less than 2 ohms between the appropriate low reference circuit listed below and ground. Seat horizontal motor sensor terminal C Seat front vertical motor sensor terminal C LHD) Seat front vertical motor sensor terminal A RHD) Seat rear vertical motor sensor terminal A (LHD) Seat rear vertical motor sensor terminal C (RHD) If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
3. Ignition ON, test for 4.8 - 5.2 V between the appropriate 5 V reference circuit terminal listed below and ground. Seat horizontal motor sensor terminal A Seat front vertical motor sensor terminal A (LHD) Seat front vertical motor sensor terminal C (RHD) Seat rear vertical motor sensor terminal C (LHD) Seat rear vertical motor sensor terminal A (RHD) If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
4. Verify the appropriate scan tool driver seat sensor parameter is less than 1.0 V. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the MSM.
5. Install a 3 A fused jumper wire between the appropriate signal circuit terminal and 5 V reference circuit terminal listed below. Verify the appropriate scan tool driver seat position sensor parameter is greater than 4.75 V. Seat horizontal position sensor terminal B and terminal A Seat front vertical position sensor terminal B and terminal A (LHD) Seat front vertical position sensor terminal B and terminal C (RHD) Seat rear vertical position sensor terminal B and terminal C (LHD) Seat rear vertical position sensor terminal B and terminal A (RHD) If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, test or replace the appropriate seat position sensor.

B1850 01 or B1850 06

1. Ignition OFF, disconnect the harness connector at the lumbar motor.
2. Test for less than 2 ohms between the appropriate low reference circuit terminal listed below and ground: Terminal C (LHD) Terminal D (RHD) If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
3. Ignition ON, test for 4.8 - 5.2 V between the appropriate 5 V reference circuit terminal listed below and ground: Terminal D (LHD) Terminal C (RHD) If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
4. Verify the scan tool Lumbar Sensor parameter is less than 1.0 V. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
5. Install a 3 A fused jumper wire between the signal circuit terminal E and the appropriate 5 V reference circuit terminal listed below. Verify the scan tool Lumbar Sensor parameter is greater than 4.75 V. Terminal D (LHD) Terminal C (RHD) If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, test or replace the lumbar position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Tilt Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Front Seat Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Driver Seat Outer Adjuster Rear Vertical Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
4. «Front Seat Recliner Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
5. «Seat Lumbar Sub System Replacement (without AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Seat Lumbar Sub System Replacement (with AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
6. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The memory seat module (MSM) controls the seat, recline, lumbar, and steering column motors via half bridges that are divided into 2 groups that are connected to separate power rails internal to the module. The MSM connects all of the motor control circuits on each power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 volts. The MSM checks to see if this reference voltage is shorted to ground or battery before enabling any seat, lumbar, or steering column motor.

The MSM must be powered.

B3920 01

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

B3920 02

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

B3921 01

The voltage on any power rail 2 motor control circuit exceeds 2.78 volts for 100 ms.

B3921 02

The voltage on any power rail 2 motor control circuit is below 1.47 volts for 100 ms.

The MSM will not allow operation of any motor on the power rail for which the DTC was set.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

1. «Driver Seat Schematics»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Passenger Seat Schematics»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

B3920 01 or B3920 02

1. Ignition OFF, disconnect the X1 harness connector at the MSM.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuits listed below and ground: Front vertical motor terminal 12 Front vertical motor terminal 13 Rear vertical motor terminal 15 Rear vertical motor terminal 16 Seat horizontal motor terminal 9 Seat horizontal motor terminal 10 If the test lamp illuminates, test the control circuit for a short to voltage.
3. Test for infinite resistance between the control circuits listed below and ground: Front vertical motor terminal 12 Front vertical motor terminal 13 Rear vertical motor terminal 15 Rear vertical motor terminal 16 Seat horizontal motor terminal 9 Seat horizontal motor terminal 10 If not the specified value, test the control circuit for a short to ground.
4. Ignition OFF, disconnect the X4 harness connector at the MSM.
5. Ignition ON, verify that a test lamp does not illuminate between the control circuits listed below and ground: Lumbar horizontal motor terminal 12 Lumbar horizontal motor terminal 13 Seat recline motor terminal 15 Seat recline motor terminal 16 If the test lamp illuminates, test the control circuit for a short to voltage.
6. Test for infinite resistance between the control circuits listed below and ground: Lumbar horizontal motor terminal 12 Lumbar horizontal motor terminal 13 Seat recline motor terminal 15 Seat recline motor terminal 16 If not the specified value, test the control circuit for a short to ground.
7. If all circuits test normal, replace the MSM.

B3921 01 or B3921 02

1. Ignition OFF, disconnect the X1 harness connector at the MSM.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuits listed below and ground: Steering column telescope motor terminal 7 Steering column telescope motor terminal 8 If the test lamp illuminates, test the control circuit for a short to voltage.
3. Test for infinite resistance between the control circuits listed below and ground: Steering column telescope motor terminal 7 Steering column telescope motor terminal 8 If not the specified value, test the control circuit for a short to ground.
4. Ignition OFF, disconnect the X4 harness connector at the MSM.
5. Ignition ON, verify that a test lamp does not illuminate between the control circuits listed below and ground: Steering column tilt motor terminal 7 Steering column tilt motor terminal 8 If the test lamp illuminates, test the control circuit for a short to voltage.
6. Test for infinite resistance between the control circuits listed below and ground: Steering column tilt motor terminal 7 Steering column tilt motor terminal 8 If not the specified value, test the control circuit for a short to ground.
7. If all circuits test normal, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Tilt Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Front Seat Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Driver Seat Outer Adjuster Rear Vertical Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
4. «Seat Lumbar Sub System Replacement (without AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Seat Lumbar Sub System Replacement (with AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
5. «Front Seat Recliner Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
6. «Steering Column Tilt Wheel Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)
7. «Steering Column Telescope Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column)
8. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

Symptoms - Power Seats

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) 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. Refer to the system description and operation from the following list in order to familiarize yourself with the system functions: «Power Seats System Description and Operation»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system__power-seats-system-description-and-operation) «Lumbar Support Description and Operation (Without Memory-A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) «Lumbar Support Description and Operation (With Memory-A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) «Memory Seats Description and Operation»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system__memory-seats-description-and-operation)

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the power seats. Refer to «Checking Aftermarket Accessories»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect the seat adjuster track for conditions which may cause binding or objects within the seat adjustment range which obstruct movement or interfere with wiring.

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

1. «Lumbar Support Inoperative (Without memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Lumbar Support Inoperative (With memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Memory Seat Feature Inoperative»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Power Seat Inoperative (Without memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Power Seat Inoperative (With memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Power seat lumbar support without memory is completely controlled through the seat lumbar adjuster switch. Battery voltage is supplied at all times to the seat lumbar adjuster switch from the RT/FRT/PWR/SEAT 25 A circuit breaker that is located in the rear fuse block. When the seat lumbar adjuster switches are in an inactive state, the switch contacts are closed to the switch ground circuit.

The lumbar motor is reversible. For example, when the lumbar horizontal forward switch is pressed to move the lumbar support forward, battery voltage is applied through the switch contacts and the lumbar motor forward control circuit to the motor. The motor is grounded through the lumbar motor rearward switch contacts and the lumbar motor rearward control circuit to the motor. The motor runs in order to drive the lumbar support forward toward the occupants back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Schematic Reference

Passenger Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Lumbar Support Description and Operation (Without Memory-A45)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

1. Disconnect the harness connector at the lumbar adjuster switch.
2. Test for less than 1 ohms between the ground circuit terminals listed below and ground: Terminal A Terminal C If greater than the specified range, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal D and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Connect the harness connector at the lumbar adjuster switch and disconnect the harness connector at the lumbar motor.
5. Ignition ON, verify that a test lamp illuminates between control circuit terminal 1 and control circuit terminal 2 while pressing the lumbar switch in both directions. If the test lamp does not illuminate for either direction, test the control circuits for a short to ground or an open/high resistance. If the circuits test normal replace the lumbar adjuster switch.
6. If the circuits test normal replace the lumbar motor.

Lumbar Adjuster Switch

1. Ignition OFF, disconnect the harness connector at the lumbar adjuster switch.
2. Test for infinite resistance between each control terminal listed below and the B+ terminal D with the switch in the open position. Lumbar horizontal forward switch terminal B Lumbar horizontal rearward switch terminal E If not the specified value, replace the lumbar adjuster switch.
3. Test for less than 1 ohm between each control terminal listed below and the B+ terminal D with the switch in the closed position. Lumbar horizontal forward switch terminal B Lumbar horizontal rearward switch terminal E If greater than the specified range, replace the lumbar adjuster switch.
4. Test for less than 1 ohms between each control terminal and the ground terminal listed below with the switch in the open position. Lumbar horizontal forward switch terminal B and terminal C Lumbar horizontal rearward switch terminal E and terminal A If greater than the specified range, replace the lumbar adjuster switch.

Lumbar Motor

1. Ignition OFF, disconnect the harness connector at the lumbar motor.
2. Install a 30 A fused jumper wire between the control terminal 1 and 12 V. Momentarily install a jumper wire between the control terminal 2 and ground. The lumbar motor should momentarily perform the FORWARD function. If the function does not perform as specified, replace the lumbar motor.
3. Reverse the polarity of jumper wires; the a lumbar motor should perform REARWARD function. If the function does not perform as specified, replace the lumbar motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver Seat Lumbar Control Switch Replacement (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Driver Seat Lumbar Control Switch Replacement (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Passenger Seat Lumbar Control Switch Replacement (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Passenger Seat Lumbar Control Switch Replacement (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Seat Lumbar Sub System Replacement (without AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Seat Lumbar Sub System Replacement (with AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Battery voltage is supplied at all times to the memory seat module (MSM) from the 10 A MSM fuse. This voltage is used by the MSM for logic power and to supply battery reference voltage to the seat and lumbar adjuster switches. Battery positive voltage is also supplied at all times to the MSM from the LF/FRT/PWR/SEAT 25 A circuit breaker. This voltage is connected to a power rail internal to the MSM and is used to drive the power seat motors, lumbar motors, and seat heater elements on vehicles equipped with heated seats. Each seat and lumbar adjuster motor is controlled by the MSM through 2 motor control circuits. The MSM connects all motor control circuits on the power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 volts. The MSM checks to see if the reference voltage is shorted to ground or battery before enabling any of the seat or lumbar motors.

The lumbar motor is reversible. For example, when the lumbar switch is operated to move the lumbar support forward, battery positive voltage is applied through the switch contacts and the lumbar horizontal forward switch signal circuit to the MSM. In response to this signal, the MSM applies battery voltage through the lumbar motor forward control circuit and ground through the lumbar motor rearward control circuit to the motor. The motor runs to drive the lumbar support forward toward the occupants back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Lumbar Support Description and Operation (With Memory-A45)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify that all manual power seat functions operate when being controlled by the seat adjuster switches. If all seat functions do not operate, refer to «Power Seat Inoperative (With memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) .
2. Ignition ON, observe the scan tool Memory Seat Module lumbar switch parameters while pressing the lumbar switch. The reading should change between Inactive and Active. If the reading does not change between the specified values, refer to the Lumbar Switch Circuit Test.
3. If all lumbar switch inputs to the MSM function normal, refer to the Lumbar Motor Control Circuit Test.

Lumbar Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the lumbar adjuster switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal D and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
3. Verify that the scan tool lumbar switch parameters are Inactive. If not the specified value, test the appropriate signal circuit listed below for a short to voltage. If the circuit tests normal, replace the MSM. Lumbar forward terminal B Lumbar rearward terminal E
4. Install a 3 A fused jumper wire between the appropriate signal circuit listed below and the B+ circuit terminal D. Verify the scan tool lumbar switch parameter is Active. Lumbar forward terminal B Lumbar rearward terminal E If not specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
5. If all circuits test normal, test or replace the lumbar adjuster switch.

Lumbar Motor Control Circuit Test

1. Ignition OFF, disconnect the harness connector at the lumbar motor.
2. Connect a test lamp between control circuit terminal A and control circuit terminal B.
3. Ignition ON, command the lumbar motor in the forward and rearward directions with a scan tool. The test lamp should turn ON when commanding the forward and rearward states. If the test lamp remains OFF during either of the commands, test the motor control circuits for an open/high resistance. If the circuits test normal replace the MSM.
4. If all circuits test normal, test or replace the lumbar motor.

Lumbar Switch

1. Ignition OFF, disconnect the harness connector at the lumbar switch.
2. Test for infinite resistance between each signal terminal listed below and the B+ terminal D with the switch in the open position. Lumbar horizontal forward switch terminal B Lumbar horizontal rearward switch terminal E If not the specified value, replace the lumbar switch.
3. Test for less than 1 ohms between each signal terminal listed below and the B+ terminal D with the switch in the closed position. Lumbar horizontal forward switch terminal B Lumbar horizontal rearward switch terminal E If greater than the specified range, replace the lumbar switch.

Lumbar Motor

1. Ignition OFF, disconnect the harness connector at the appropriate lumbar motor.
2. Install a 30 A fused jumper wire between the control terminal A and 12 V. Momentarily install a jumper wire between the control terminal B and ground. The lumbar motor should momentarily perform the FORWARD function. If the function does not perform as specified, replace the lumbar motor.
3. Reverse the polarity of jumper wires; the a lumbar motor should perform REARWARD function. If the function does not perform as specified, replace the lumbar motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver Seat Lumbar Control Switch Replacement (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Driver Seat Lumbar Control Switch Replacement (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Seat Lumbar Sub System Replacement (without AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Seat Lumbar Sub System Replacement (with AHS)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Reference voltage is supplied to the memory switch from the driver door module (DDM). When a memory switch is pressed, battery voltage is applied through the switch contacts, a series of resistors and thorough the memory switch signal circuit to the DDM. The door module then sends a serial data message to the memory seat module (MSM) indicating the memory recall request. The MSM then commands the appropriate seat motors to move to the pre-recorded seat positions stored in memory in response to the switch input.

The DDM is referenced in Tech 2 as the Driver Door Switch.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that all manual power seat and lumbar functions operate as described in the description and operation. Refer to «Power Seat Inoperative (Without memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Power Seat Inoperative (With memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Lumbar Support Inoperative (Without memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Lumbar Support Inoperative (With memory A45)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) .
2. The memory seat module (MSM) cannot perform Memory Seat Recall, Easy Exit Setup, or Easy Exit Recall functions unless these options are activated in the driver information center (DIC). Refer to the Owners Manual to verify that these memory recall personalization options are ON.
3. Verify that memory positions for driver 1 and driver 2 have been recorded to memory by observing the scan tool Driver Position Module, Memory Data 1 and Memory Data 2 parameters.

1. Ignition ON, verify the scan tool Driver Door Switch Memory Recall Switches parameter is approximately 2.75 volts while pressing the memory 1 switch. If not the specified value, perform the Memory Switch component test. If the switch tests normal, replace the driver door module.
2. Verify the scan tool Memory Recall Switches parameter is approximately 1.75 volts while pressing the memory 2 switch. If not the specified value, replace the memory seat adjuster switch.
3. Verify the scan tool Memory Recall Switch parameter is approximately 1.0 volt while pressing the EXIT switch. If not the specified value, replace the memory seat adjuster switch.
4. If all circuits test normal, replace the MSM.

Memory Switch

1. Disconnect the X4 harness connector at the DDM.
2. Test for infinite resistance between the memory switch signal circuit terminal 5 and the switch supply voltage circuit terminal 14. If not infinite, replace the memory seat adjuster switch.
3. Test the resistance between terminal 5 and terminal 14 while pressing the memory 1, memory 2, and EXIT buttons. Compare the resistance readings to the values in the Memory Switch Values table below. If the resistance is not within the specified range, replace the memory seat adjuster switch.

Memory Switch Values

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver Seat Adjuster Memory Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM and DDM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Power seat without memory is completely controlled through the seat adjuster switch. Battery voltage is supplied at all times to the driver seat adjuster switch from the LF/FRT/PWR/SEAT circuit breaker and the passenger seat adjuster switch from the RT/FRT/PWR/SEAT circuit breaker that are located in the rear fuse block. When the seat adjuster 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 forward control circuit to the motor. The motor is grounded through the horizontal motor rearward switch contacts and the horizontal motor rearward control circuit to the motor. 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.

Schematic Reference

1. «Driver Seat Schematics»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Passenger Seat Schematics»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)

Connector End View Reference

Component Connector End Views

Description and Operation

Power Seats System Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Operate the switches for the seat directional motors listed below in both directions. The seat should move in the commanded directions.

1. Horizontal Motor
2. Front Vertical Motor
3. Rear Vertical Motor
4. Recline Motor

1. If the power seat is inoperative in all directions, refer to the Seat Adjuster Switch Circuit Test.
2. If 1 or more of the seat adjuster motors operate, refer to the Seat Adjuster Motor Circuit Test.

Seat Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for less than 5 ohms between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal E and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, test or replace the seat adjuster switch.

Seat Adjuster Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat adjuster motor.
2. Connect a test lamp between control circuit terminal 1 and control circuit terminal 5.
3. Ignition ON, verify that the test lamp illuminates while pressing the appropriate seat switch in both directions. If the test lamp does not illuminate for both directions, test the control circuits for a short to ground or an open/high resistance. If the circuits test normal replace the seat adjuster switch.
4. If all circuits test normal, replace the seat adjuster motor.

Seat Adjuster Switch

1. Ignition OFF, disconnect the harness connector at the 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 not the specified value, replace the seat adjuster switch.
3. Test for less than 1 ohms between the B+ terminal E and each control terminal with the appropriate switch in the closed position. If greater than the specified range, replace the adjuster switch switch.
4. Test for less than 1 ohms between the ground terminal B and each control terminal with the switch in the open position. If greater than the specified range, replace the seat adjuster switch.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor.
2. Install a 30 A fused jumper wire between the control terminal 1 and 12 V. Momentarily install a jumper wire between the control terminal 5 and ground. The seat motor should momentarily perform the appropriate FORWARD/REARWARD/UP/DOWN function. If the function does not perform as specified, replace the seat motor.
3. Reverse the polarity of jumper wires; the a seat motor should perform in the opposite direction. If the function does not perform as specified, replace the seat motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Adjuster Switch Replacement - Driver Side (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Front Seat Adjuster Switch Replacement - Driver Side (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Front Seat Adjuster Switch Replacement - Passenger Side (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Front Seat Adjuster Switch Replacement - Passenger Side (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Front Seat Tilt Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
4. «Front Seat Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
5. «Driver Seat Outer Adjuster Rear Vertical Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
6. «Front Seat Recliner Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Battery voltage is supplied at all times to the memory seat module (MSM) from the 10 A MSM fuse. This voltage is used by the MSM for logic power and to supply reference voltage to the seat and lumbar adjuster switches. Battery positive voltage is also supplied at all times to the MSM from the LF/FRT/PWR/SEAT 25 A circuit breaker. This voltage is connected to a power rail internal to the MSM and is used to drive the power seat motors, lumbar motor, and seat heater elements on vehicles equipped with heated seats. Each seat and lumbar adjuster motor is controlled by the MSM through 2 motor control circuits. The MSM connects all motor control circuits on the power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 V. The MSM checks to see if the reference voltage is shorted to ground or battery before enabling any of the seat or lumbar motors.

All motors are reversible. For example, when the seat switch is operated to move the entire seat forward, battery positive voltage is applied through the switch contacts and the power seat horizontal forward switch signal circuit to the MSM. In response to this signal, the MSM 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.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Memory Seat Module seat switch parameters while pressing the appropriate seat switch. The reading should change between Inactive and Active.

1. If the reading does not change between the specified values, refer to the Seat Adjuster Switch Circuit Test.
2. If all switch inputs to the MSM function normal, refer to the Seat Adjuster Motor Circuit Test.

Seat Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal E and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
3. Install a 3 A fused jumper wire between the appropriate signal circuit listed below and the B+ circuit terminal E. Verify the appropriate scan tool seat switch parameter is Active. Front vertical upward switch terminal A (LHD) Front vertical upward switch terminal K (RHD) Front vertical downward switch terminal K (LHD) Front vertical downward switch terminal A (RHD) Rear vertical upward switch terminal F (LHD) Rear vertical upward switch terminal J (RHD) Rear vertical downward switch terminal J (LHD) Rear vertical downward switch terminal F (RHD) Horizontal forward switch terminal D Horizontal rearward switch terminal C Recline forward switch terminal H Recline rearward switch terminal G If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
4. If all circuits test normal, test or replace the seat adjuster switch.

Seat Adjuster Motor Test

1. Ignition OFF, disconnect the X3 harness connector at the MSM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the X3 harness connector at the memory seat module and disconnect the X1 harness connector at the appropriate seat adjuster motor.
4. Connect a test lamp between control circuit terminal 1 and control circuit terminal 5.
5. Ignition ON, command the appropriate seat motor in the Up/Down or Forward/Rearward directions with a scan tool. The test lamp should turn ON when commanding the up and down or forward and rearward states. If the test lamp remains OFF during either of the commands, test the control circuits for an open/high resistance. If the circuits test normal replace the MSM.
6. If all circuits test normal, test or replace the seat adjuster motor.

Seat Adjuster Switch

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for infinite resistance between the B+ terminal E and each seat direction signal terminal with the switch in the open position. If not the specified value, replace the seat adjuster switch.
3. Test for less than 1 ohms between the B+ terminal E and each seat direction signal terminal with the appropriate switch in the closed position. If greater than the specified range, replace the adjuster switch switch.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor.
2. Install a 30 A fused jumper wire between the control terminal 1 and 12 V. Momentarily install a jumper wire between the control terminal 5 and ground. The seat motor should momentarily perform the appropriate FORWARD/REARWARD/UP/DOWN function. If the function does not perform as specified, replace the seat motor.
3. Reverse the polarity of jumper wires; the a seat motor should perform in the opposite direction. If the function does not perform as specified, replace the seat motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Adjuster Switch Replacement - Driver Side (AQ9)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system) or «Front Seat Adjuster Switch Replacement - Driver Side (W2E)»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
2. «Front Seat Tilt Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
3. «Front Seat Adjuster Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
4. «Driver Seat Outer Adjuster Rear Vertical Actuator Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
5. «Front Seat Recliner Actuator Motor Replacement»(/cadillac/cts/ii-2007-2014/remont/seats/#power-seat-system)
6. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM replacement, setup, and programming

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Scheme 88

Scheme 89

Scheme 90

Scheme 91

Scheme 92

Scheme 93

Lumbar Support Components

The front passenger power seat lumbar support systems consist of the following components

1. Lumbar switch
2. Lumbar horizontal motor
3. MSM/RT FRT PWR SEAT Circuit Breaker 25 A

Lumbar Switch

The lumbar switch provides both power and ground to the lumbar motor. Battery positive voltage is supplied at all times to the lumbar adjuster switch from the MSM/RT FRT PWR SEAT Circuit Breaker located in the rear fuse block. Ground for the lumbar adjuster switch is supplied from the G300 ground stake.

Lumbar Horizontal Motor

The lumbar support system consists of a lumbar horizontal motor. The motor contains an electronic circuit breaker (PTC) that will reset only after voltage has been removed from the motor. The lumbar horizontal motor moves the lumbar support forward and rearward.

When the lumbar switch is operated to move the lumbar support rearward, battery positive voltage is applied through the lumbar rearward switch contacts and the lumbar motor rearward control circuit to the lumbar horizontal motor. The motor is grounded through the lumbar forward switch contacts and the lumbar motor forward control circuit to the horizontal motor. The motor runs to drive the lumbar support rearward away from the occupant's back until the switch is released. Moving the lumbar support forward works similarly to moving the lumbar support rearward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

The driver seat lumbar support system with memory (A45) consists of the following components

1. Lumbar switch
2. Memory seat module (MSM)
3. Lumbar horizontal motor
4. Lumbar horizontal position sensor
5. MSM LOGIC/RF MASSAGE Fuse 10 A

Battery positive voltage is supplied at all times to the driver seat lumbar switch from the memory seat module and the MSM LOGIC/RF MASSAGE Fuse located in the rear fuse block. When the lumbar switches are pressed they send a 12-volt signal to the memory seat module (MSM). The MSM then commands the lumbar motor to move in response to the switch signals.

Motors

The lumbar support system consists of the lumbar horizontal motor. The motor contains a electronic circuit breaker (PTC), which will reset only after voltage has been removed from the motor. The lumbar horizontal motor moves the lumbar support in the forward or rearward directions. The MSM controls the lumbar motor via a half bridge that is connected to a single power rail internal to the module. The MSM connects both lumbar motor outputs on the power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 volts. The MSM checks to see if this reference voltage is shorted to ground or battery before enabling any seat or lumbar motor.

Soft stop functions are not used for driver seat motors that are controlled by either a memory or non-memory MSM.

Lumbar Horizontal Movement

When the lumbar switch is operated to move the lumbar support forward, battery positive voltage is applied through the switch contacts and the driver seat lumbar forward switch signal circuit to the memory seat module (MSM). In response to this signal, the MSM applies battery positive voltage through the lumbar motor forward control circuit and ground through the lumbar motor rearward control circuit to the motor. The motor runs to drive the lumbar support forward toward the occupant's back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. The MSM also controls the lumbar horizontal motor during memory recall functions.

Lumbar Position Sensors

The lumbar position sensor is a potentiometer which is an internal part of the lumbar motor. The memory seat module (MSM) supplies a 5-volt reference voltage through the 5-volt reference circuit and ground through the low reference circuit to the lumbar position sensor. When the lumbar motor rotates, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. This voltage varies from 0.27-4.65 volts. The MSM monitors this voltage signal to determine the lumbar position.

When a memory set command is received, the MSM records the lumbar position by storing the feedback voltage from the position sensor. Then when a memory recall command is received, the MSM moves the motor until the position sensor feedback voltage equals the feedback voltage stored in memory. The lumbar support is not involved in the easy exit function.

Memory Functions

Refer to Memory Seats Description and Operation .

Memory Seats Description and Operation

The memory seat system consists of the following components

1. Memory seat module
2. Driver door lock/window switch
3. Driver seat adjuster switch
4. Driver seat lumbar adjuster switch
5. Driver memory seat adjuster switch
6. Driver seat horizontal motor
7. Driver seat front vertical motor
8. Driver seat rear vertical motor
9. Driver seat recline motor
10. Driver seat lumbar horizontal motor
11. Driver seat horizontal motor position sensor
12. Driver seat front vertical motor position sensor
13. Driver seat rear vertical motor position sensor
14. Driver seat recline motor position sensor
15. Driver seat lumbar horizontal motor position sensor

Memory Recall Option

The memory seat module (MSM) cannot perform Memory Seat Recall and Easy Exit functions unless these options are activated in the driver information center (DIC), refer to the Owner's Manual. The DIC reports the memory recall option setting to the MSM, as well as other receiving modules, via GMLAN message each time the ignition switch is cycled to the ON position. The MSM will then store the memory recall option setting and examine it before making a memory seat adjustment. The memory recall option setting stored within the MSM will not change until the memory recall option setting in the DIC is changed and the ignition switch is cycled to the ON position.

Power Seat and Lumbar Switches

Battery positive voltage is supplied at all times to the driver seat adjuster switch and lumbar adjuster switch from the MSM and a 10 A fuse located in the rear fuse block. When the seat or lumbar switches are pressed they send a 12 V signal to the MSM. The MSM commands the selected seat or lumbar motor to move in response to the switch inputs.

MSM Power and Grounds

Battery positive voltage is supplied at all times to the MSM through a 25 A circuit breaker located in the rear fuse block. This voltage is used by the MSM to apply power to the driver seat, lumbar, and steering wheel and column motors when commanded ON. Battery positive voltage is applied at all times to the MSM through a 10 A fuse also located in the rear fuse block. This voltage is used to power up MSM. Ground is provided to the MSM through two separate ground circuits that are connected to a common ground.

MSM Controlled Motors

The MSM controls all seat, lumbar, and steering wheel and column motors via half bridges that are connected to a single power rail internal to the module. The MSM connects all motor outputs on the power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 V. The MSM checks to see if this reference voltage is shorted to ground or voltage before enabling any seat, lumbar, or steering wheel and column motor. All of the motors operate independently of each other. Each motor contains a electronic circuit breaker (PTC), which will reset only after voltage has been removed from the motor.

All MSM controlled motors are reversible. For example, when a seat switch is pressed to move the entire seat forward, battery voltage is applied through the switch contacts and seat horizontal forward switch signal circuit to the MSM. In response to this signal, the MSM 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 in order to drive the entire seat forward. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. All of the motors are powered this way.

Position Sensors

The position sensors are potentiometers which are either attached directly to the motor transmission cable or are an internal part of the motor. The MSM supplies a 5 V reference through the 5 V reference circuit and ground through the sensor low reference circuit to the respective seat, lumbar, and steering and column position sensors. For more information regarding the steering wheel and column, refer to Steering Wheel and Column Description and Operation . When the motor or cable rotates, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. The voltage varies from 0.22 - 4.75 V. The MSM monitors this voltage signal to determine the position of the seat. When a memory set command is received, the MSM records the seat position by storing the feedback voltage from each position sensor. Then when a memory recall command is received, the MSM moves the motors until the position sensor feedback voltages equals the feedback voltages stored in memory.

Battery voltage is supplied at all times to the driver memory seat adjuster switch from the driver door lock/window switch that is located on the driver door panel. When a memory button is pressed, battery voltage is applied through the switch contacts, a series of resistors, and the memory recall switch signal circuit to the driver door lock/window switch. In response to this signal, the driver door lock/window switch sends a serial data message to the MSM indicating the memory request.

Memory positions may be recorded for 2 different drivers. To record a position, adjust the driver's seat, lumbar support, and steering wheel and column to the desired position. Press and hold the memory 1 button until two beeps sound indicating that the position has been stored to memory. A second memory position may be programmed by repeating the above steps and pressing button 2, for driver 2. When the MSM receives a memory set message, it records the feedback voltages from the seat, lumbar, and adjustable pedals position sensors for the appropriate driver.

When a memory recall button is pressed, a single beep will sound to acknowledge the command has been received. The MSM will then move the appropriate seat, lumbar, and steering wheel and column until the position sensor feedback voltages equal the feedback voltages stored in memory for the identified driver.

Memory recall operation is disabled if the shift lever is out of NEUTRAL (N) or PARK (P). The memory seat module receives the transmission selector position data via the GMLAN Serial Data circuit.

Easy Exit

If the EASY EXIT SEAT function is activated in the DIC as mentioned above, the driver seat will automatically move rearward approximately 3 inches when the key is removed from the ignition. If desired, the seat may be moved further by pressing the EXIT button. The seat will move approximately 3 inches each time the EXIT button is pressed until it reaches its end of travel. When the EXIT button is pressed, a single beep will sound to acknowledge the command. The Easy Exit incremental movement distance cannot be adjusted; it is pre-programmed at the factory.

Recall Personalization

Refer to the owners manual for the following memory personalization options

1. Recall upon receipt of the RKE message
2. Recall upon receipt of the remote start feature
3. Easy exit
4. Factory settings

Memory Inhibit/Enable

The MSM receives the ignition switch signal and the gear selector position via GMLAN messages. When the ignition switch is in the OFF position, memory record, memory recall, personalization recall, and exit recall functions are all allowed. When the ignition switch is in the ON position and the gear selector is in the PARK position, only the recall personalization function is deactivated and all other memory functions are allowed. When the ignition switch is in the ON position and the gear selector is out of the PARK position, only memory record is allowed, all other memory seat functions are not allowed.

Power Seats System Description and Operation

The driver and front passenger power seat systems each consist of the following components

1. Seat Adjuster Switch
2. Seat Horizontal Motor
3. Seat Front Vertical Motor
4. Seat Rear Vertical Motor
5. Seat Recline Motor
6. MSM/LT FRT PWR SEAT Circuit Breaker 25 A
7. MSM/RT FRT PWR SEAT Circuit Breaker 25 A

Seat Adjuster Switch

Battery positive voltage is supplied at all times to the driver and front passenger seat adjuster switches from their respective Circuit Breakers that are located in the rear fuse block. Both seat adjuster switches are grounded through the switch ground circuit and G 300. The seat adjuster switches provide both power and ground to the selected seat motors.

All of the seat motors operate independently of each other. Each motor contains an electronic circuit breaker (PTC) that will reset only after voltage has been removed from the motor. There are four seat position motors. These are the horizontal motor, front vertical motor, rear vertical motor, and the seat back recline motor. The horizontal motor moves the entire seat forward and rearward. Both vertical motors run simultaneously when the seat switch is operated to move the entire seat up and down. Or they can be selected independently to vertically tilt the front or rear of the seat up and down. The recline motor moves the angle seat back forward and rearward.

Horizontal

When the seat switch is operated to move the entire seat forward, battery positive voltage is applied through the horizontal motor forward switch contacts and the horizontal motor forward control circuit to the motor. The motor is grounded through the horizontal motor rearward switch contacts and the horizontal motor rearward control circuit to the motor. 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.

Rear Vertical

When the seat switch is operated to tilt the rear of the seat up, battery positive voltage is applied through the rear vertical motor up switch contacts and the rear vertical motor up control circuit to the rear vertical motor. The motor is grounded through the rear vertical motor down switch contacts and the rear vertical motor down control circuit to the rear vertical motor. The motor runs in order to drive the rear of the seat up until the switch is released. Tilting the rear of the seat down works similarly to tilting the rear of the seat up, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Front Vertical

When the seat switch is operated to tilt the front of the seat up, battery positive voltage is applied through the front vertical motor up switch contacts and the front vertical motor up control circuit to the front vertical motor. The motor is grounded through the front vertical motor down switch contacts and the front vertical motor down control circuit to the front vertical motor. The motor runs in order to drive the front of the seat up until the switch is released. Tilting the front of the seat down works similarly to tilting the front of the seat up, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Entire Seat Up or Down

When the seat switch is operated in order to move the entire seat to the up position, battery positive voltage is simultaneously applied through the front and rear vertical motor up switch contacts and the front and rear vertical motor up control circuits to both vertical motors. The motors are grounded through the front and rear vertical motor down switch contacts and the front and rear vertical motor down control circuits to both vertical motors. Both motors run simultaneously in order to drive the entire seat up until the switch is released. Moving the entire seat down works similarly to moving the entire seat up, except that battery positive voltage and ground are applied on the opposite circuits causing the motors to run in the opposite direction.

Recline

When the seat recline switch is operated to move the seat back forward, battery positive voltage is applied through the recline motor forward switch contacts and the recline motor forward control circuit to the recline motor. The motor is grounded through the recline motor rearward switch contacts and the recline motor rearward control circuit to the recline motor. The motor runs in order to move the seat back forward until the switch is released. Moving the seat back rearward works similarly to moving the seat back forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Tilt/Telescoping Steering Column Schematics
• Checking Aftermarket Accessories
• Driver or Passenger Seat Adjuster Switch Bezel Replacement (AQ9)
• Front Side Door Trim Panel Replacement
• Fastener Caution
• SIR Disabling and Enabling
• Driver or Passenger Seat Side Inflatable Restraint Module Replacement (CTS)
• Steering Wheel and Column Description and Operation
• DTC B1335
• Memory Seats Description and Operation
• Power Seats System Description and Operation