Circuit/System Testing
WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition ON, verify that the instrument panel cluster (IPC) warning indicators are illuminated.
- If the IPC warning indicators are not illuminated, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the IPC.
- Ignition OFF, disconnect the harness connector X1 at the ECM.
- Ignition ON, verify the MIL is not illuminated.
- If the MIL is illuminated, test the MIL control circuit for a short to ground. If the circuit tests normal, replace the IPC.
- Connect a 3 A fused jumper wire between the MIL control circuit, terminal 12-X1, and ground. The MIL should illuminate.
- If the MIL does not illuminate, test the MIL control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.
- If all circuits test normal, replace the ECM.