Ground Circuits
- Turn ignition off. Using an ohmmeter, check continuity between chassis ground and ECM ground terminals. See GROUND TERMINAL IDENTIFICATION table. Ohmmeter should indicate zero ohms. If reading is not zero ohms, check and repair open circuit between ECM connector and ground.
- Connect voltmeter negative lead to chassis ground. Connect positive lead to ECM ground terminals. See GROUND TERMINAL IDENTIFICATION table. See Figure . With engine running, voltmeter should indicate less than one volt. If voltmeter reading is greater than one volt, check for open, corrosion or loose connection in ground circuit.