Code P0118 - Engine Coolant Temperature Sensor High
- Connect and operate scan tester, following manufacturer's instructions. Turn ignition on. Read engine coolant temperature. If indicated temperature is less than -22°F (-30°C), go to next step. If indicated intake air temperature is not less than -22°F (-30°C), problem is intermittent. Inspect for poor connections or loose wires at ECT sensor and ECM, then repair as necessary.
- Turn ignition off. Unplug ECT sensor. Connect Green/White and Red/White wires together at ECT sensor harness connector. Turn ignition on. Read intake air temperature. If indicated intake air temperature is less than -22°F (-30°C), go to next step. If indicated intake air temperature is not less than -22°F (-30°C), temporarily substitute known good ECT sensor, then retest system.
- Turn ignition off. Connect ECM harness connector terminals D7 (Red/White wire) and D11 (Green/White wire). Turn ignition on. Read intake air temperature. If indicated intake air temperature is not less than -22°F (-30°C), repair open Red/White or Green/White wire. If indicated intake air temperature is less than -22°F (-30°C), temporarily substitute known good ECM, then retest system.