SLK 55 AMG (171.473) V8-5.5L (113.989) (2005)
Heater Control Valve: Description and Operation
GF83.20-P-2100-01SK Duovalve Function
GF83.20-P-2100-01SK Duovalve Function
Function
The duovalve (Y21) is directly actuated by:
^
the HEAT control and operating unit (N18) (without code (580a) automatic air conditioning, without code (581b) comfort automatic air
conditioning),
^
the AAC control and operating unit (N22) (with code (580a) automatic air conditioning) or
^
the comfort AAC control and operating unit (N22/7) (with code (581b) comfort automatic air conditioning)
The duovalve (Y21) controls the flow of coolant through the heater heat exchanger separately for the right and left sides.
The closing and opening times of the duovalve (Y21) depend on the target temperature that has been selected in the vehicle interior.