Turn the ignition switch ON (II). At the engine wire harness side, measure voltage between the ECT sensor 2P connector terminal No. 2 and body ground. ECT SENSOR 2P CONNECTOR Wire side of female terminals Is the about 5 V? YES - Go to step 9. NO - Go to step 10. Measure voltage between the ECT sensor 2P connector terminals No. 1 and No. 2. ECT SENSOR 2P CONNECTOR Wire side of female terminals Is there about 5 V? YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/PCM. NO - Repair open in the wire between the ECM/PCM (A10) and the ECT sensor. Turn the ignition switch OFF. Disconnect the climate control unit 22P connector. Turn the ignition switch ON (II).

At the engine harness side, measure voltage between the ECT sensor 2P connector terminal No. 2 and body ground. ECT SENSOR 2P CONNECTOR Wire side of female terminals Is there about 5 V? YES - Replace the climate control unit. NO - Go to step 14. Measure voltage between ECM/PCM connector terminal B8 and body ground. ECM/PCM CONNECTOR B (24P) Wire side of female terminals Is there about 5 V? YES - Repair open in the wire between the ECM/PCM (B8) and the ECT sensor. NO - Go to step 15.