If it's low on Freon, has a bad low pressure switch, or a bad high pressure switch, the ecm won't ground (engage) the relay. Make sure it has Freon (at least 30 psi), if it does, jumper the low pressure switch. If it kicks in, the switch is bad. If not that, a scanner would help narrow it down.

 

I had everything replaced last year. They checked everything over again this time around.

 

The only way to know if it's the pcm itself is to diagnose with a scanner, to see if a/c is being requested and to check low and high pressure switches.

 

Can I check that with v2?

 

bump. Someone else would have to answer that.

 

Anyone? Anyone?

I know lb7 ecms can be problematic Could it be EFI live issue?

 

EFI can from what peole say. Mine did that and the ambient air temp sensor in the bumper (not the one by the trans cooler) was toast.

 

Maybe after work ill flash stock tune back in and see if anything changes

 

Tried reflashing. No change. Might just have to get new ECM... I don't drive truck alot but AC would be nice when I do since it's hitting 90s

 

i was having the same problem a few weeks ago. then it started working again.. but now i get code 0107 low voltage to the map sensor and when i clear the code my fuel guage quits working until the code pops up again... tested volts going to the map sensor and only have .01 volts think its the pcm