The outdoor air temperature sensor on a 2008 Mazda X3 is located beneath the front crash beam behind the front grill. It displays the temperature on a gauge located inside the vehicle. The sensor control temperature and blower speeds.
A frequent complaint regarding this sensor stemmed from a delay in the gauge displaying the correct temperature. According to Mazda, the sensor is programmed to display the correct ambient temperature once certain thresholds are met. The sensor displays the actual ambient temperature if the vehicle has been parked overnight before starting. Otherwise, it increases by 0.5 degrees after driving for 90 seconds at a speed in excess of 20 miles-per-hour and increases by a degree for every minute of continuous driving afterward until it reaches the correct temperature. The sensor is programmed not to increase when the vehicle is in stop-and-go traffic or if the speed drops below 20 miles-per-hour.