Ambient Temperature Sensor: Notes
The temperature function is supported by the ambient temperature sensor, a wiring circuit, and the Body Control Module (BCM). If any portion of the ambient temperature sensor circuit fails or if the Controller Area Network (CAN) data bus information is missing, a (- -) will appear in the Electronic Vehicle Information Center (EVIC) display in place of the temperature. When the sensor is exposed to temperatures above 55°C (130°F), or if the sensor circuit is shorted, 55°C (130°F) will appear in the EVIC display in place of the temperature. When the sensor is exposed to temperatures below -40°C (-40°F) or if the sensor circuit is open, -40°C (-40°F) will appear in the EVIC display.
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 64 km/h (40 mph). 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 (4 hrs. 15 min.). This strategy was intended to eliminate wildly fluctuating readings and may cause some customer confusion leading to unnecessary diagnostics/parts replacements.
The ambient temperature sensor circuit can be diagnosed using the following Sensor Test, and Sensor Circuit Test. If the temperature sensor and circuit are confirmed to be OK, but the temperature display is inoperative or incorrect, test the EVIC operation. Refer to CENTER, ELECTRONIC VEHICLE INFORMATION, DIAGNOSIS AND TESTING .