Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Seat Adjuster Switch Circuit Test
- Ignition OFF, disconnect the harness connector at the seat adjuster switch.
- 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.
- Install a 3 A fused jumper wire between the appropriate signal circuit listed below and the B+ circuit terminal E. Verify the scan tool seat switch parameter is Active.
- Front vertical upward switch terminal A
- Front vertical downward switch terminal K
- Rear vertical upward switch terminal F
- Rear vertical downward switch terminal J
- 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.
- If all circuits test normal, test or replace the seat adjuster switch.
Seat Motor Control Circuit Test
- Ignition OFF, disconnect the X3 harness connector at the MSM.
- 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.
- Ignition OFF, connect the X3 harness connector at the MSM and disconnect the X1 harness connector at the seat adjuster motor assembly.
- Connect a test lamp between the appropriate control circuits listed below:
- Seat horizontal motor terminal 3 and terminal 6
- Seat front vertical motor terminal 2 and terminal 5
- Seat rear vertical motor terminal 1 and terminal 4
- 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.
- If all circuits test normal, test or replace the seat motor.
Recline Motor Control Circuit Test
- Ignition OFF, disconnect the harness connector at the recline motor.
- Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
- Ignition ON, command the Recline Forward/Rearward 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 control circuits for an open/high resistance. If the circuits test normal, replace the MSM.
- If all circuits test normal, test or replace the recline motor.