U1510 Code - Bad HVAC Control Module

[xSHIFTxNASTYx]

Getting a check engine light, reads U1510, no K code.

Tuner is reading it as "faulty HVAC control module".

Anyone dealt with this before?

 

Have searched the forum with no luck on this particular K code. They all refer to other K codes under U1510 and suggesting to remove connectors, clean them, maybe add dielectric grease, and reseat. Well, obviously this one isn't going to be easy to get to. They also suggest removing the negative battery cable for quite some time then try again. Tried that, didn't help. Odd thing with this CEL is it only comes on if I try to remote start my truck. Went a week with manually starting with the key, no CEL. As soon as I try remote start, throws a CEL and won't remote start. Otherwise, truck runs fine with no other issue.

 

EDIT: Wanted to add that I have no issues with my HVAC, air is cold with A/C and heat is hot when cranked up. Only noticeable issue is changing fan speed seems to have a delay now, 2-4 seconds before fans ramp up or slow down. Related? I don't know.

 

Is this control module in the dash? I hope not. I hate dash work.

 

Don't think I want to go to stealership yet. Read a lot of talk about them not having a generic starting point with U1510 due to complexity of K codes so usually ends up being a 3-5 day ordeal. Not interested.

Edited January 8, 2021 by xSHIFTxNASTYx

[NewUsers]

2017 Sierra Denali, 32k miles. Back in December my light came on, I checked it with my scanner and I got P0449, P2101 and U1510. Erased all codes and P0449 and U1510 came back. Gave my truck to the dealership, said they fixed it under warranty. I picked it up and light was still on.. they fixed P0449 (chafed wire on the rear chassis wire harness?) but appeared to ignore the U1510??!? Researched U1510 til my eyes started bleeding, changed the Grille Shutter this past weekend, erased the code, light is still on. I'm not super electrically inclined but I have a multimeter and Power Probe. Really trying to fix this myself and not waste more time at the dealership  I see many others have had this issue with the grille shutters

 

Is there a fuse for the grille shutter circuit? Anyone have any pointers please?