DTC Troubleshooting: 1

DTC 1:  An Open in the In-car Temperature Sensor Circuit

1.Remove the in-car temperature sensor.

2.Measure the resistance between the No. 1 and No. 2 terminals of the  in-car temperature sensor.
*Check for change in resistance by heating or cooling the sensor with a hair dryer.

 

*Is the resistance within the specifications shown on the graph?


YES -

  • LHD type: Go to 3.
  • RHD type: Go to 6.

NO - Replace the  in-car temperature sensor.n


3.Disconnect the climate control unit 36P connector.

4.Check for continuity between the No. 8 terminal of the climate control unit 36P connector and the No. 1 terminal of the in-car temperature sensor 4P connector.

 

Is there continuity?


YES - Go to 5.


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


5.Check for continuity between the No. 2 terminal of the climate control unit 36P connector and the No. 2 terminal of the in-car temperature sensor 4P connector.

 

Is there continuity?


YES - Check for loose wires or poor connections at the climate control unit 36P connector and at the in-car temperature sensor 4P 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 in-car temperature sensor.n

6.Disconnect the climate control unit 36P connector.

7.Check for continuity between the No. 8 terminal of the climate control unit 36P connector and the No. 2 terminal of the in-car temperature sensor 2P connector.

 

Is there continuity?


YES - Go to 8.


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


8.Check for continuity between the No. 2 terminal of the climate control unit 36P connector and the No. 1 terminal of the in-car temperature sensor 2P connector.

 

Is there continuity?


YES - Check for loose wires or poor connections at the climate control unit 36P connector and at the in-car temperature 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 in-car temperature sensor.n