Outside Temperature Display Sensor: Testing and Inspection

AMBIENT TEMPERATURE SENSOR

The ambient temperature sensor located below the front bumper is a Negative Temperature Coefficient (NTC) thermistor. The internal resistance of the sensor is reduced as the ambient temperature rises. The BCM continually monitors the resistance through the sensor to determine the temperature value to be displayed. The current value is displayed immediately after the display unit is activated. The display value will remain static regardless of decreases in the sensor resistance (temperature rising) below vehicle speeds of 10 to 15 kilometers-per-hour (6 to 9 miles-per-hour). Decreases in the sensor resistance above 15 kilometers-per-hour (9 miles-per-hour) and increases in the sensor resistance (temperature falling) regardless of vehicle speed are displayed subject to a sixty second delay.

SENSOR TEST

1. Turn the ignition switch to the Off position. Disconnect the ambient temperature sensor harness connector, Removal.
2. Measure the resistance of the ambient temperature sensor. At - 40° C (- 40° F), the sensor resistance is 336 kilohms. At 55° C (130° F), the sensor resistance is 2.488 kilohms. The sensor resistance should read between these two values. If OK, further testing of the instrument cluster may be necessary. If not OK, replace the inoperative ambient temperature sensor.