Outside temperature sensor

The outside temperature sensor is directly connected to the auxiliary instrument. The auxiliary instrument supplies the outside temperature sensor with voltage. The ambient temperature is displayed in the top liquid crystal display. The auxiliary instrument makes the ambient temperature available for other systems on the K-CAN.

Fig 1: Outside Temperature Sensor - Circuit Diagram

Courtesy of BMW OF NORTH AMERICA, INC.

The signal from the outside temperature sensor is digitized in the auxiliary instrument. A calculation model suppresses the effects of thermal radiation from the engine compartment on the signal. At higher driving speeds and lower engine temperatures the system selects lower damping action. The real outside temperature value can only be reliably expected starting at driving speed of about 80 km/h.