Ambient Temperature Sensor
WARNING: This page is about a different car, the 2005 BMW 645Ci and 2004 BMW 645Ci. However, it is still accessible from the selected car via links, so may be relevant.
The ambient temperature sensor supplies the value for the temperature outside the vehicle to the instrument cluster. The ambient temperature is shown on the LCD display. Instrument resolution is 0.5 °C (1 °F). The value for ambient temperature is also made available to other control units via the K-CAN.