Diagnosis And Testing - Ambient Temperature Sensor: Notes
The temperature function is supported by the ambient temperature sensor, a wiring circuit, and the Totally Integrated Power Module (TIPM). When the sensor is exposed to temperatures above 60° C (140° F), or if the sensor circuit is shorted, 60° C (130/140° F) will appear in the 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, - - ° C (- - ° F) will be displayed on Electronic Vehicle Information Center (EVIC) equipped vehicles.
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.