Parking Heater

If the car is equipped with a parking heater, the Automatic Climate Control (ACC) unit is activated by the parking heater with a 12 V timer signal. The Automatic Climate Control (ACC) unit then sends a 12 volt "wake up signal" to pin 3 on the Electronic Display Unit (EDU) control module. The control module then starts to measure and indicate outside temperature and sends pulses showing current outside temperature from pin 23 to the ACC unit.

Other functions in the control module are shut off.