Ambient Air Temperature Sensor

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The ambient air temperature sensor is a 2-wire negative temperature co-efficient thermistor. A 5-volt reference and signal circuit enables the sensor to operate. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor signal varies between 0-5 volts. The IPC receives input from the ambient air temperature sensor and converts the signal to a working temperature range.

The ambient temperature range is between -40°C (-40°F) and 60°C (140°F). If the ambient temperature is below 3°C (37°F), the temperature display will toggle every 8 seconds for 2 minutes between the outside temperature and the word ICE. After 2 minutes the ICE feature is disabled. When the temperature is less than -40°C (-40°F) or when there is an open in the circuit for more than 2 seconds, OC displays. When the temperature is above 60°C (140°F) or when there is a short in the circuit for more than 2 seconds, SC displays.

The ambient air temperature sensor is mounted in the forward engine area of the vehicle. In this position, it is exposed to the airflow through the grill before it reaches the radiators.

The DIC displays the ambient air temperature value that it receives from the instrument panel cluster (IPC). The ambient air temperature is updated or displayed under the following conditions:

Driver Information Center (DIC) Description and Operation

Conditions	Display
At start up with the engine off more than 3 hours	Displays real-time temperature
At start up with the engine off equal to or less than 3 hours	Displays last stored temperature
Vehicle speed is more than or equal to 16 km/h (10 mph)	Displays real-time temperature
Vehicle speed is less than 16 km/h (10 mph)	Displays last temperature stored while driving above 16 km/h (10 mph)