Operation CHARM: Car repair manuals for everyone.
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DTC 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 a change in resistance by heating or cooling the sensor with a hair drier.

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

YES - Go to step 3.

NO - Replace the in-car temperature sensor.

3. Disconnect climate control unit connector B (22P).




4. Check for continuity between the No.16 terminal of climate control unit connector B (22P) and the No.1 terminal of the in-car temperature sensor 2P connector.

Is there continuity?

YES - Go to step 5.

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





5. Check for continuity between the No.9 terminal of climate control unit connector B (22P) and the No.2 terminal of the in-car temperature sensor 2P connector.

Is there continuity?

YES - Check for loose wires or poor connections at climate control unit connector B (22P) 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

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