Lumbar Massage Inoperative
Lumbar Massage Inoperative
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
Battery voltage is supplied to the driver seat and front passenger seat lumbar massage switches from the memory seat module (MSM). When the lumbar massage switch is pressed, battery voltage is applied through the switch contacts and the lumbar massage signal circuit to the MSM. The MSM then cycles battery voltage and ground through the lumbar vertical motor control circuits to the lumbar vertical motor for 10 minutes or until the massage function is canceled. The MSM supplies the lumbar vertical position sensor with a 5-volt reference and low reference circuits. When the motor rotates, the resistance of the potentiometer varies changing the voltage of the lumbar vertical position sensor signal to the MSM.
Diagnostic Aids
The memory seat module is referenced in the Tech 2 as the Driver Position Module.
Reference Information
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Memory Seats Description and Operation (Memory Seats)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
1. Ignition ON, verify that all manual seat lumbar functions operate when being controlled by the seat lumbar switches.
• If all manual seat lumbar functions do not operate, refer to Lumbar Support Inoperative Lumbar Support Inoperative.
2. Ignition ON, observe the appropriate scan tool Massage Switch parameter while pressing the appropriate lumbar massage switch. The reading should change between Inactive and Active.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate lumbar massage switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal C and ground.
• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
3. Install a 3A fused jumper wire between the B+ circuit terminal C and the signal circuit terminal A. Verify the Massage Switch parameter is Active.
• 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 tests normal, replace the lumbar massage switch.
Component Testing
Lumbar Massage Switch
1. Ignition OFF, disconnect the harness connector at the lumbar massage switch.
2. Test for infinite resistance between the signal terminal A and the B+ terminal C with the switch in the open position.
• If not the specified value, replace the lumbar massage switch.
3. Test for less than 1 ohm between the signal terminal A and the B+ terminal C with the switch in the closed position.
• If greater than the specified range, replace the lumbar massage switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver or Passenger Seat Lumbar Control Switch Replacement (Driver or Passenger Seat Lumbar Control Switch Replacement)
* Control Module References (Programming and Relearning)for MSM replacement, setup, and programming