Temperature Sensor

Before testing the rear air temperature sensor, verify that the front A/C system is operating correctly by performing the ATC Function Test using the DRBIII(R) scan tool. For circuit descriptions and diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
1. Disconnect and isolate the battery negative cable.
2. Unplug the wire harness connector for the rear air temperature sensor.
3. Measure the resistance of the temperature sensor. At -40° C (-40° F), the sensor resistance is 336 kilohms. At 55° C (131° F), the sensor resistance is 25 kilohms. The sensor resistance should read between these two values.
4. If OK, test and repair the rear air temperature sensor wire harness circuits. If not OK, replace the faulty air temperature sensor.