Can anyone tell me the exact location of the Cayenne S Heater Control valve ( Pierburg 955 572 824 05) - is it under dash left or right side, or back of engine perhaps. I cannot locate it, nor find any reference online.

My AC is running HOT AIR all the time - all vents, regardless of AC temp is set - and I heard this could be due to malfunctioning HVAC heater Control valve - which I purchased , but cannot find on the vehicle

many thanks, mike