Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2010 GMC Yukon XL, 2010 GMC Yukon, 2010 Chevrolet Tahoe, 2010 Chevrolet Suburban, and 2010 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Lumbar Switch Circuit Test
- Ignition OFF, disconnect the harness connector at the lumbar switch.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal G 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.
- Verify that all scan tool Memory Seat Module 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 horizontal forward terminal C
- Lumbar horizontal rearward terminal B
- Lumbar vertical upward terminal F
- Lumbar vertical downward terminal A
- 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.
- Install a 3A fused jumper wire between the appropriate signal circuit listed below and the B+ circuit terminal G. Verify the scan tool Lumbar Switch parameter is Active.
- Lumbar horizontal forward terminal C
- Lumbar horizontal rearward terminal B
- Lumbar vertical upward terminal F
- Lumbar vertical downward terminal A
- If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
- If all circuits test normal, test or replace the lumbar switch.
Lumbar Motor Control Circuit Test
- Ignition OFF, disconnect the X1 harness connector at the lumbar adjuster motor assembly.
- Connect a test lamp between the appropriate control circuits listed below:
- Lumbar horizontal motor terminal C and terminal D
- Lumbar vertical motor terminal A and terminal B
- Ignition ON, command the appropriate lumbar 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.
- If all circuits test normal, test or replace the lumbar adjuster assembly.