TXSZ66AVLANCHE

iTrader: (7)

Friday morning my AC quit working, assumed it was a leak in the lines or something typical. When I got back home and hooked up the gauges it showed that the system was full, there is no AC request signal coming from the PCM. Armed with a stack of diagrams I painfully checked every related wire for continuity, all check out good. With my scanner hooked up there is no values showing in any of the AC pressure sensors. Jumping the ac relay turns on the compressor and there is nice cold air. So as of now it looks like a bad PCM, bummer since I have been waiting forever for my updated PCM, hopefully it gets here before the end of summer.

Anyone have any other ideas?

TXSZ66AVLANCHE

iTrader: (7)

AC fixed! There was a break inside the insulation for the 5v reference wire to the high pressure sensor. With slack on the harness the 5v reference was there, when tension was on the harness or with the weight of the harness hanging there was no 5v reference. Was able to pinpoint the bad area and splice in a new section of wire and its good to go now. Thanks for all the replies lol

00ChevyScott

iTrader: (10)

Glad to see you got it figured out. I knew it had to be a messed up wire somewhere.

TXSZ66AVLANCHE

iTrader: (7)

For what its worth...all of the diagnostic aids all pointed towards the PCM being bad. Also the code needs to be cleared in order for the AC to work again after the repair, problem with that is you can only read and clear this particular code with a Tech2 and lucky for me I know someone that has one.

00ChevyScott

iTrader: (10)

I'm sure you could do it with HPTuners or EFIlive as well. Hell you could do a complete rewrite and it would fix it if you had to.

And these PCMs rarely go bad.

TXSZ66AVLANCHE

iTrader: (7)

Don't have EFI or HP, don't have nothing to tune with. I was never sold on the bad PCM, my Cutlass had a bad PCM and it affected more than the AC...cruise and several other functions would not work either.

My updated PCM is supposed to finally be here this week! Its been a long long wait, really need to look into HPT or EFI Live so I can make changes whenever.