ECM Power and Ground Supply Circuit Check

Power Supply Circuit:

INSPECTION
- Disconnect the negative battery cable.
- Disconnect the ECM connectors.
- Connect the negative battery cable.
- Turn key ON.
- Check for battery voltage between ECM harness terminals:
23 and ground
108 and ground
111 and ground
- Check for continuity between ECM harness terminals:
108 and ground
112 and ground

RESULTS AND CORRECTION
- If voltage was not present at terminals 23, 108 or 111, check the following:
Main relay
Ignition switch
Fuses
Fuse links
Wiring continuity
- If continuity did not exist between terminals 109 and ground or 112 and ground check the following.
All ECM ground points
Wiring continuity
- If voltage and continuity results were satisfactory, the power and ground circuit to the ECM is OK.