Ambient Temperature Sensor / Switch HVAC: Description and Operation

Outside Temperature Sensor
The outside temperature is obtained from the SID, the temperature sensor of which is mounted under the front bumper.

The outside temperature is used by the ACC control module to correct the cabin temperature and also to control the fan speed.

Cabin temperature is corrected so that it corresponds to the physical perception of the selected temperature. This means that the actual cabin temperature is higher than the selected temperature at low outside temperatures. Even at high outside temperatures the actual cabin temperature is higher than the selected temperature, but the difference is less. This depends on whether heat passes from the cabin to the outside air or vice versa.

At outside temperatures below +5 °C and above +20 °C, fan speed increases to achieve a more uniform cabin temperature.

On connection of the Parking heater, the SID is woken up by the ACC control module and starts sending the outer temperature to it.