The HeVAC Module constantly cuts the compressor on and off. I traced the problem back to the AirCon Request and Grant signals to the BeCM.
My request goes from 12v to .6v and just constantly fluctuates when I get over 15mph. When it goes high, it kills the compresser, when it goes back to low, it cuts on. The HeVAC just constantly toggles between turning it on and off.
If I accelerate or rapidly increase my RPM's, the HeVAC will keep the AC on, but as soon as my RPM's get under 1500 rpm's, it goes back to the oscillations.
The compresser will stay on if the RR is under 15 mph.
I have replaced the clutch, all pressure switches, and tried to verify the output of the various sensors.
Any idea's?
davebl @ mac . com