• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Climate Control no AC weird error

Sontours

New Member
Joined
Nov 2, 2016
Messages
5
Location
Rockledge, FL
OK I have a 2004 Avalanche. Replaced compressor and recharged system. Worked great for a day. Now I have intermittent AC. I am in Florida and it is needed. Here is what I have checked, high and low pressure, fuses, relay etc. What I am finding is that I am not getting a signal to turn on the compressor even thought the snowflake is on.
I used my scanner and read the Body module and here is where it is weird.
In the Engine control module the engine temp is 193.
In the HVAC control module it says my engine temp is -40. It shows that the AC permission is granted and that ac switch is off. I can push the ac button and the switch will say On then quickly goes to Off.
I replaced the climate control module last fall and it was doing the same thing and then worked fine for a couple months.
I am not sure who knows the guts of this system and where it gets that -40 temp reading since all other scans show normal engine temp.

Any thoughts?
Thanks,
Phil
 
DId you check Low pressure switch on Accumulator? when they go bad AC does not work as it thinks it is low pressure even though it may be fine.
 
Yes I have jumped it, checked it and replaced it. I think it is fine. I am just curious as to why the HVAC module would show -40 as the engine temperature. I feel this is where the problem is coming from.

Thanks for the reply.

Phil
 
Back
Top