Malfunction Indicator lamp (MIL), Functional Check

Function test:
- Switch on ignition: exhaust MIL must light up.

If exhaust MIL does not light up when ignition is switched on:
- Check wire from ECM to exhaust MIL as follows:







If exhaust MIL does not light up when ignition is switched on, continue test as follows:
- Start engine and let run at idle: Exhaust MIL must go out after a few seconds.

If exhaust MIL does not go out:
- Check DTC memory.

If there no DTCs are stored:







- Read readiness code. If DTC memory was erased or the Engine Control Module (ECM) was disconnected from the continuous B+ supply, the readiness code must be re-generated.

Refer to "Monitors, Trips and/or Drive Cycle (Readiness Code)/Reading Readiness Code" and "Monitors, Trips and/or Drive Cycle (Readiness Code)/Generating Readiness Code" under "Powertrain Management/Computers and Control Systems" Testing and Inspection