Lumbar Support Inoperative

LUMBAR SUPPORT INOPERATIVE

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

CIRCUIT/SYSTEM DESCRIPTION
B+ is supplied to the lumbar adjuster switch from the PWR SEAT circuit breaker. Ground is supplied to the lumbar adjuster switch from G301. When the lumbar adjuster switch is pressed to increase or decrease lumbar support, the lumbar adjuster switch provides voltage and ground to the appropriate terminals of the seat lumbar motor.

CIRCUIT/SYSTEM TESTING
1. Disconnect the lumbar adjuster switch.
2. Ignition ON, verify that a test lamp illuminates between the ground circuit terminal A and B+.
- If the test lamp is OFF, test the affected circuit for an open, high resistance, or short to voltage.
3. Verify that a test lamp illuminates between the ground circuit terminal C and B+.
- If the test lamp is OFF, test the affected circuit for an open, high resistance, or short to voltage.
4. Verify that a test lamp illuminates between the B+ circuit terminal D and ground.
- If the test lamp is OFF, test the affected circuit for an open, high resistance, or short to ground.
5. Ignition OFF, reconnect the lumbar adjuster switch.
6. Disconnect the seat lumbar motor.
7. Ignition ON, connect a test lamp between the inflate circuit terminal 1 and ground.
8. Press and release the lumbar adjuster switch in the Inflate position. The test lamp should turn ON and OFF when pressing and releasing the switch.
- If the test lamp is always ON, test the circuit for a short to voltage. If the circuit tests normal, replace the lumbar adjuster switch.
- If the test lamp is always OFF, test the circuit for an open, high resistance, or short to ground. If the circuit tests normal, replace the lumbar adjuster switch.
9. Connect a test lamp between the deflate circuit terminal 2 and ground.
10. Press and release the lumbar adjuster switch in the Deflate position. The test lamp should turn ON and OFF when pressing and releasing the switch.
- If the test lamp is always ON, test the circuit for a short to voltage. If the circuit tests normal, replace the lumbar adjuster switch.
- If the test lamp is always OFF, test the circuit for an open, high resistance, or short to ground. If the circuit tests normal, replace the lumbar adjuster switch.
11. If all circuits test normal, replace the lumbar motor.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Lumbar Switch Replacement
- Front Seat Lumbar Support Replacement