Lumbar Switch Circuit Test
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- 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.