ECT Sensor Circuit Troubleshooting

1.Check the malfunction indicator lamp (MIL).

Does the malfunction indicator lamp come on?


YES - Refer to the power train DTCs.


NO - Go to 2.


2.Turn the ignition switch OFF.

3.Disconnect the ECT sensor 2P connector.

4.Disconnect climate control unit 28P connector.

5.Turn the ignition switch ON (II).

6.Measure the voltage between the No. 24 terminal of climate control unit 28P connector and body ground.

 

Is there about 5 V?


YES - Check for loose wires or poor connections at climate control unit 28P connector and at the ECT sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original  climate control unit.n


NO - Repair open in the wire between the climate control unit and the ECT sensor.n