Circuit/System Testing
WARNING: This page is about a different car, the 2010 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the X1 harness connector at the K67 trailer brake control module.
- Connect a test lamp between the signal circuit terminal 14 and ground.
- Ignition ON, command the Center Brake Lamp ON and OFF with a scan tool. The test lamp should turn ON and OFF while changing between the commanded states.
- If the test lamp is always ON, test the signal circuit for a short to voltage.
- If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance.
- If all circuits test normal, replace the K67 trailer brake control module.