Hvac
Thread Starter
Racer
Joined: Oct 2002
Posts: 449
Likes: 2
From: Fayetteville, PA
Hvac
I know this issue has been discussed hundreds of times, but my issue seems to be different in one way then the others. When I start my car for the first time the HVAC lights up and works just fine. When I shut the ignition after a ride or just out of the garage and turn the car off, then start it again I get no communication. After a few minutes it comes back on. This is different from most of the posts I read on the Forum. Anyone have any ideas? Thanks in advance. Black 1997 with dual control head.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
You get NO COMMS with what modules???????? There are SEVERAL things that pop into mind. You need to further define what symptoms that you are seeing. First things first. Clear ALL of your DTCs. Does it just effect the HVAC module or some other modules???? The DTCs will help define the issue.
When the problem happens, READ the DTCs using the C5 DIC and post up ALL the DTCs on all of the modules. NOTE!!! Its highly recommended that you read the DTCs when the problems happens BUT,,,,,,,,,,,,,,,,, DO NOT turn the ignition off and back ON. Read the DTCs in the ignition cycle that they happen in and post up the results. If you have warning messages in the DIC, just press and hold RESET for each warning until they go away.
When the problem happens, READ the DTCs using the C5 DIC and post up ALL the DTCs on all of the modules. NOTE!!! Its highly recommended that you read the DTCs when the problems happens BUT,,,,,,,,,,,,,,,,, DO NOT turn the ignition off and back ON. Read the DTCs in the ignition cycle that they happen in and post up the results. If you have warning messages in the DIC, just press and hold RESET for each warning until they go away.
Thread Starter
Racer
Joined: Oct 2002
Posts: 449
Likes: 2
From: Fayetteville, PA
Started the car and had P0135c P0155c p1571h C1243h 0432hc AC No Comm
Reset and started C1571hc HVAC NoComm
Usually the unit works after a few minutes but not today.
Reset and started C1571hc HVAC NoComm
Usually the unit works after a few minutes but not today.
Last edited by 77BlueL82; Mar 11, 2019 at 04:11 PM. Reason: change
Racer
Joined: Mar 2013
Posts: 477
Likes: 48
You don't say how many miles are on the car but I was having some of the same issues and after I replaced the ignition switch all of the no comm issues went away. The contacts inside the switch end up with burnt tips that can't send a clean signal to the computer and thus the codes you are seeing. It's an easy, and cheap(about 60.00) repair you can do in about an hour. Search it in the tech forum or online and I would bet that would fix your problem. Good luck.
