2011 kw t800 climate control calibration

Have been having problems with the ac system on a 2011 T800.
It will blow hot with the ac working. For some reason the control unit will open the heater valve when it should shut it. Heatervalve has been replaced several times since these things are prone to fail. Which in this instance doesn't do anything since the controller opens it. Is there a way to calibrate or reset this?. Alos is there a wiring diagram? thanks in advance.