Outside Temperature Display Sensor: Testing and Inspection

AMBIENT TEMPERATURE SENSOR

The thermometer function is supported by the ambient temperature sensor, the Totally Integrated Power Module (TIPM), the Controller Area Network (CAN) data bus circuit, and the instrument cluster or Cab Compartment Node (CCN) compass/temperature display unit.

NOTE: The system displays the last known temperature when starting the vehicle and may take some time/mileage to update to an accurate current reading, up to 5 minutes at a maintained speed above 40 mph (64.3 kph). Customers with very short commutes may not get an updated reading before the vehicle is turned off, or if the ignition does not remain in the OFF position for more than 255 minutes (4hrs. 15min.). This strategy was intended to eliminate wildly fluctuating readings and may cause some customer confusion leading to unnecessary diagnostics/parts replacements.

If the display shows " _ _ _ ", there is an OPEN or SHORT CIRCUIT that must be repaired. The ambient temperature sensor can be diagnosed using the following Sensor Test.

SENSOR TESTING

1. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable.
2. Disconnect the ambient temperature sensor wire harness connector.
3. Measure the resistance of the ambient temperature sensor. At room temperature (approx. 20° C (68°F)), the sensor resistance should be between 9-11 Kilohms (9000-11000 ohms). The sensor resistance should read between these two values. If OK, refer to the appropriate diagnostic information to continue diagnosis of the Totally Integrated Power Module (TIPM), the Controller Area Network (CAN) data bus circuit, and the instrument cluster or CCN. If not OK, replace the inoperative ambient temperature sensor.
The most reliable, efficient and accurate means to diagnose the ambient temperature circuit requires the use of a scan tool and the proper diagnostic procedure information. Refer to wiring for the appropriate information.