Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
- Ignition ON, verify the scan tool hood position parameter displays Open.
- If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
- 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 sort 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 connector X1 at the ECM.
- Ignition ON, verify the MIL is not illuminated.
- If the MIL is illuminated, inspect the MIL control circuit for a short to ground. If the circuit tests normal, replace the IPC.
- Ignition ON, verify that the MIL illuminates with a 3A fused jumper between the MIL control circuit, ECM terminal X1-12, and ground.
- 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 ECM.