Chart A-1 - No Check Engine Light: Notes

There should always be a steady CHECK ENGINE light when ignition is on and engine is stopped. Battery voltage is supplied to bulb through C7 fuse. The Electronic Control Module (ECM) turns the light on by providing a ground path through Violet wire.

1. Battery voltage at circuit No. 240 is protected by a fusible link, located in relay/fuse box under the hood, near the battery.
2. If voltage is present on circuit No. 240, check for faulty ECM ground or ECM.
3. Using a test light connected to 12 volts, probe each system ground circuit to ensure a good ground is present.