Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- With the ignition OFF, disconnect the ECM, turn ON the ignition with the engine OFF.
- If the MIL remains illuminated, test the MIL control circuit for a short to ground.
- If the MIL control circuit tested OK and the MIL remained illuminated, replace the instrument panel cluster (IPC).
- If the MIL control circuit tested OK and the MIL turned OFF when the ECM was disconnected, replace the ECM.
- With the ignition ON, measure the MIL control circuit for 12 volts at the ECM harness connector to a ground.
- If there is less than 12 volts, test the MIL ignition voltage and MIL control circuits for the following:
- An open
- A short to ground
- An open fuse
- If there is less than 12 volts, test the MIL ignition voltage and MIL control circuits for the following:
- Remove the fuse that supplies power to the MIL with a DMM, measure for less than 1 volt from the MIL control circuit in the ECM harness connector to a good ground.
- If there is more than 1 volt, test the MIL control circuit for a short to voltage or a faulty IPC.
- Install MIL fuse, the MIL should illuminate when a 3-amp fused jumper wire is connected between the MIL control circuit and a good ground.
- If the MIL does not illuminate, test the MIL control and MIL voltage circuits for less than 10 ohms of resistance.
- If the resistance is over 10 ohms, repair the high resistance in the circuit that measured over 10 ohms.
- If the MIL control and voltage circuit tests OK, replace the IPC.
- If the MIL illuminates, but does not illuminate when commanded ON with a scan tool, replace the ECM.