Air Door Vacuum Solenoid Valve: Description and Operation

The valve block controls the vacuum for actuation of the vacuum elements.

Eight switchover valves are integrated into the switchover valve block (Y11). Various voltage pulses are required in a certain number and sequence to actuate a valve. The voltage pulses come from the A/C push-button control module (N22).
The electronic circuitry in the switchover valve block (Y11) recognizes the voltage pulses and actuates the corresponding switchover valve to supply vacuum to the vacuum element in question.

The following vacuum elements are actuated:
- Left defroster nozzle flap vacuum element
- Right defroster nozzle flap vacuum element
- Center nozzle diverter flap vacuum element
- Fresh air/recirculated air flap vacuum element
- Left center nozzle blend flap vacuum element
- Right center nozzle blend flap vacuum element
- Left footwell flap vacuum element
- Right footwell flap vacuum element