GM Service Manual Online
For 1990-2009 cars only

Ambient Temperature Sensor Description CJ4

The outside air temperature sensor is located in the front grill area under the front bumper of the vehicle. The HAVC control head uses this sensor to receive information on ambient air temperature. With this information, the HVAC control head will give the driver the outside air temperature on the digital display. If the outside temperature increases, the displayed temperature will not change until:

    • The vehicle's speed is above 32 km/h (20 mph) for approximately one and a half minutes.
    • The vehicles speed is above 72 km/h (45 mph) for approximately one minute.

These delays help prevent false readings. If the displayed temperature goes down, the outside temperature display is updated immediately. If the vehicle has been turned off for more than three hours, the current outside temperature will be shown when the vehicle is started. If it has been turned off for less than three hours, the temperature will be recalled from the previous vehicle operation.