Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector of the stop lamp switch.
- Ignition ON, verify that a test lamp illuminates between the stop lamp switch voltage circuit terminal B and ground.
- If the test lamp does not illuminate, test the stop lamp switch voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the RUN/CRANK PCB Relay.
- Ignition OFF, disconnect the harness connectors of the BCM C5, ECM C1, and the TCM.
- Verify that a test lamp does not illuminate between the stop lamp switch TCC brake signal circuit terminal A and B+.
- If the test lamp illuminates, test the TCC brake signal circuit for a short to ground.
- Test for less than 1.0 ohm resistance between the stop lamp switch TCC brake signal circuit terminal A and the ECM connector C1 terminal 9.
- If greater than the specified range, test the TCC brake signal circuit for an open/high resistance.
- If all circuits test normal, replace the stop lamp switch.