PWM cooling fan(s) control using ECM

[parsonsj]

Originally Posted by Scot

So with the GMPP controller (I believe it is an E67), there is no point adding the AC pressure sensor/switch? Unless the BCM is added?

It would be better if the A/C request went through the ECM so we could have compressor protection features (like RPM limit, WOT cutoff, overheating protection, etc.). But we don't, so all we get are fan control features via the A/C pressure sensor. Is it worth doing? I think so, but it isn't ideal, and the system needs a binary switch to protect the compressor since the ECM doesn't/can't.

If only Vintage Air or InfinityBox (nee ISIS) had support for GM's A/C CAN-bus request...