Chart A-1, No Check Engine Light

The CHECK ENGINE light should remain on when ignition switch is in ON position and engine is not running. ECM activates CHECK ENGINE light by completing a ground circuit.

1. Completing a ground circuit should illuminate the CHECK ENGINE light.
2. Checks for B+ from the control relay.
3. Verifies battery voltage to control relay from ignition switch.
4. Verifies a good ground circuit from ECM connector to ground.
5. If test light illuminates, this indicates a faulty control relay.