When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
so the controls down the console that run the HVAC system do not work, and have triggered a check engine light. The codes show ”no communication with HVAC module” (U0164). But the HVAC controls within the infotainment system on the screen work perfectly for all functions. Why is that? If the HVAC module is bad, how can the controls still work on the screen? Am I to assume that that’s because they go directly to the ECU and bypass the module? I understand that the buttons down the console for HVAC is actually the module , they don’t work at all except the on off switch which turns off the default defrost position. Comments?
I have done the battery reset, opened up the console and checked all the connectors, all to no avail… I’m taking it in later in the week. Just curious if somebody is up on this situation…
Warranty... I would not take things apart in attempt to self-diagnose as you then run the risk of damaging something further and having the failure blamed on you. There is something electrical wrong somewhere within the system, and it'll likely required either a reprogramming of a module, or the replacement of a module and/or wire harness.
so I took it into the dealer today, and it was a worthless visit, because when I got there, I was told that the GM technician has taken sick and had to go home. But the service advisor did pull all the codes for the GM system. it looks to me as if it’s more serious than just an AC module. My question is: from a technical standpoint, is the car set up so that if one module fails, a significant amount of other modules may lose communication because it’s some type of daisy chain? here is what they found. I don’t even have a front camera! Any comments would be helpful. I am scheduled to go back in late next week. Meanwhile, the car continues to run perfectly and generate no warnings, panels, messages, etc.… And also meanwhile, my Chevy app continues to tell me that my car is 100% healthy and nothing is wrong… What a worthless app…
I suspect a singular control module or the connection to it is to blame. Everything likes to "talk" to everything perhaps through a singular module. Should be easy to pinpoint the failure point. In the meantime, enjoy putting miles on your car.
I found a certified Chevy tech online and he reiterated that the module will cause all the rest of those faults, and it’s no problem to drive the car, and most likely a pin that isnt making contact in the hvac connector in the console. it goes in to the dealer in 10 days.
help diagnosing an HVAC problem.
