For 1990-2009 cars

This sensor (2) is located in front of the radiator The heater and A/C programmer processes the sensor data. The sensor data displays on the heater and A/C control.

During periods of city traffic and idle conditions, engine heat surrounds the area of the outside temperature sensor, causing temperature readings that are higher than the actual ambient air temperature.

In order to help eliminate these false readings, programming techniques are used in order to minimize unwanted temperature variations.

The outside air temperature sensor uses a memory feature in order to help provide greater accuracy under engine restart conditions:

• | If the engine coolant temperature is less than 10°C (18°F) above the outside temperature sensor reading, the actual sensed outside temperature displays.

• | If the engine coolant temperature is greater than 10°C (18°F) above the outside temperature sensor reading, a memorized outside temperature displays. This memorized temperature was sensed when the engine was previously operating.

When the vehicle reaches or maintains a speed of 32 km/h (20 mph), the outside temperature display may increase, after a built-in 80 second time delay. This delay allows the outside air to cool the sensor.

If the sensor reading is ever less than the displayed value, or if the vehicle speed is at least 72 km/h (45 mph), the outside temperature changes are displayed as rapidly as possible.

The driver may update the outside temperature display by pressing the following buttons simultaneously:

• | For Pontiac and Oldsmobile:

- | AUTO

- | A/C

- | RECIRC

• | For Buick:

- | AUTO

- | VENT

- | RECIRC