DTC P0118: Engine Coolant Temp. (ECT) Circuit High Input
- Connect scan tool to Data Link Connector (DLC). Turn ignition on. Select ECT parameter. If display reads -40°F (-40°C), go to next step. If display reading is not -40°F (-40°C), check for an intermittent problem. See TESTS W/O CODES article.
- Turn ignition off. Disconnect ECT sensor harness connector located near coolant outlet. Turn ignition on. Measure voltage between ground and Light Green/Red wire of ECT sensor harness connector. If reading is 4-6 volts, go to next step. If reading is greater than 6 volts, check Light Green/Red wire for short to battery power. If reading is less than 4 volts, check Light Green/Red wire for an open. Repair as necessary. If wiring is okay, replace PCM.
- Turn ignition off. Disconnect PCM harness connector "B". Check continuity between PCM harness connector "B", terminal No. 9 and Green/Red wire at ECT sensor harness connector. If continuity exists, go to next step. If continuity does not exist, check Green/Red wire for an open or poor connection. Repair as necessary.
- Connect PCM harness connector. Turn ignition on. Using a fused jumper wire, jumper terminals of ECT sensor harness connector together. If display on scan tool reads 246°F (119°C), replace ECT sensor. If display reading is not 246°F (119°C), replace PCM.