Can the dealer reprogram my HVAC control module to latest software?

[Diesel6point6]

Hi guys. I've been trying to figure out why my rear HVAC won't change temp. The mode actuator works as it should, but the blend door actuator just overclocks itself to the AC side everytime I reset it. It doesn't go the other way (heat side).

I've verified the actuator itself works by hooking it up to a 9V, it moves in both directions. But I've replaced it just to rule it out and still no dice.

I've read the rear HVAC control module that I have is a version known to cause issues (P/N 15185966) and the latest version (P/N 15832319) is the one to get. Problem is, it's proved to be just about impossible to find 15832319 anywhere since it's a discontinued part. I even went to a salvage yard to try and get lucky. I went through probably 20-25 vehicles and not 1 had that latest part #. The newest part # I found was 21997590 (it's the 2nd newest version apparently) so I grabbed it just to give it a shot and the actuator still behaves the same (overclocks itself) I'm rather suspicious this is my issue since I've verified the actuator is funtional, and the blend door moves freely.

So my question is, do y'all know if I can bring one of my old hvac modules to the dealer and they can re-program it to essentially turn it into 15832319?

 

[swathdiver]

Hi guys. I've been trying to figure out why my rear HVAC won't change temp. The mode actuator works as it should, but the blend door actuator just overclocks itself to the AC side everytime I reset it. It doesn't go the other way (heat side).

I've verified the actuator itself works by hooking it up to a 9V, it moves in both directions. But I've replaced it just to rule it out and still no dice.

I've read the rear HVAC control module that I have is a version known to cause issues (P/N 15185966) and the latest version (P/N 15832319) is the one to get. Problem is, it's proved to be just about impossible to find 15832319 anywhere since it's a discontinued part. I even went to a salvage yard to try and get lucky. I went through probably 20-25 vehicles and not 1 had that latest part #. The newest part # I found was 21997590 (it's the 2nd newest version apparently) so I grabbed it just to give it a shot and the actuator still behaves the same (overclocks itself) I'm rather suspicious this is my issue since I've verified the actuator is funtional, and the blend door moves freely.

So my question is, do y'all know if I can bring one of my old hvac modules to the dealer and they can re-program it to essentially turn it into 15832319?

They should be able to, get a Tech-2 on it and do a proper diagnosis first.

 

[SnowDrift]

Hi there. I'm new to the forum, today. I have been searching for a solution to this same problem with the rear no-heat issue. Winter is upon us and I've recently discovered I only have cold air blowing from the ceiling vents. I highly suspect the module (P/N 15832319, 21997590, Dorman 601-036, Delco 15-73506), but it seems that they no longer exist on planet earth - at least for the time being.

Has anyone resolved this on a temporary basis, in terms of physically moving the blend doors to be able to get heat on the floor, rather than cold air on the ceiling? I'm not opposed to doing so, but want to do it in a safe manner so that once the correct part becomes available, I can replace it and not have an issue.

 

[George B]

Hi there. I'm new to the forum, today. I have been searching for a solution to this same problem with the rear no-heat issue. Winter is upon us and I've recently discovered I only have cold air blowing from the ceiling vents. I highly suspect the module (P/N 15832319, 21997590, Dorman 601-036, Delco 15-73506), but it seems that they no longer exist on planet earth - at least for the time being.

Has anyone resolved this on a temporary basis, in terms of physically moving the blend doors to be able to get heat on the floor, rather than cold air on the ceiling? I'm not opposed to doing so, but want to do it in a safe manner so that once the correct part becomes available, I can replace it and not have an issue.

You can drive the actuators with a 9v battery or open them up and manually move the gears.
Getting a Tech2 on it and diagnosing the issue would be a big help too.

 

[SnowDrift]

I had a thought a few minutes ago that someone may have already posted a solution like I'm seeking, so I checked out the tube and ran across this. Perhaps it will be useful to someone in the future for the same issue:

"rear hvac system only blows cold air (diagnosis and temporary fix)" is part of the title

 

[SnowDrift]

Thanks - how can I operate with a 9V battery? I'm all ears.

I guess the video link won't work, but hopefully someone can search by the title I supplied.

 

[George B]

Thanks - how can I operate with a 9V battery? I'm all ears.

I guess the video link won't work, but hopefully someone can search by the title I supplied.

 

[George B]

I had an issue with our mode door once where it would run cal and then sit in one position no matter what I did. Even bought a new one with the same issue. Once I got a tech2 I could diagnose it. I found out that the BCM thought it was in the wrong position. I opened it up and manually turned it to the center while watching the counts on the data stream. I had to move the little POT to the correct position and reinstall the gear. I did a calibration after and it has worked for two years now.

 

[SnowDrift]

I appreciate the clip. I will see if I can get access to a Tech 2