No Rear Heat

[clix]

Not a novel issue (several threads I have read pasted below for reference), but my 05 Yukon does not blow heat from the rear floor or ceiling vents. There is airflow from each of the vents but only cold air. Based on what I have read, it seems that the rear A/C control module is probably the problem (replacement part: http://www.amazon.com/gp/product/B000S2SHZK/ ).

In the last thread below the service bulletin lists a couple DTCs related to the issue. My question is will these DTCs necessarily be triggered if the control module is the problem? I don't see a trouble code when hooking up to a scantool but am not sure if my neighbor's tool/software has all the functionality to read the DTC (ScanXL with GM add-on).

http://tahoeyukonforum.com/forum/showthread.php?t=66875
http://tahoeyukonforum.com/forum/showthread.php?t=66406
http://tahoeyukonforum.com/forum/showthread.php?t=59198
http://tahoeyukonforum.com/forum/showthread.php?t=34521
http://tahoeyukonforum.com/forum/showthread.php?t=59224
http://tahoeyukonforum.com/forum/showthread.php?t=12635

Thanks in advance!

 

[kev92gt]

Had same problem on my 03 I posted link this week. I'll find give me a sec.

---------- Post added at 11:50 PM ---------- Previous post was at 11:48 PM ----------

https://www.youtube.com/watch?v=oeWG5hTRW8s
Here you go!

 

[clix]

Had same problem on my 03 I posted link this week. I'll find give me a sec.

---------- Post added at 11:50 PM ---------- Previous post was at 11:48 PM ----------

https://www.youtube.com/watch?v=oeWG5hTRW8s
Here you go!

Thanks! Did you happen to see if there was a DTC set before changing it out?

 

[jdabest]

Fixed mine yesterday, works like a champ now. The video is very helpful.

 

[clix]

Fixed mine yesterday, works like a champ now. The video is very helpful.

JDA, did you happen to check to see if there was DTC before you bought the part and changed it out? I'm trying to avoid ordering the part until I'm sure that is the problem.

 

[kev92gt]

Thanks! Did you happen to see if there was a DTC set before changing it out?

DTC is? I pretty much just followed the video.

 

[jdabest]

No codes, just changed it out. No problems since I changed it.

 

[xobrian]

I changed this out on my 03 Yukon a few months ago, followed that same video and no problems.

 

[OR VietVet]

DTC is? I pretty much just followed the video.

Diagnostic Trouble Code.

 

[clix]

So, I did not have a DTC but bought the part anyway and it fixed the problem, at least part of it. Took me less time than I thought, the only midly frusting part was getting the upper passenger side plastic piece back into place (couldn't see where the snaps needed to line up).

Now I get heat from the ceiling vents but not the floor vents. There is no air coming from the floor vents, regardless of which setting I have the rear vents set to.

 

[Red Rider]

I think the DTCs would be read only on certain readers. I doubt your average code reader would pull any specific GM codes. If you have a Tech-2, might work for you.

When I had rear issue, i had no trouble/engine light come on. But Don't know if a GM code would trigger this. Maybe a message on the dash readout?

---------- Post added at 08:59 AM ---------- Previous post was at 08:54 AM ----------

You missed my post on this. http://tahoeyukonforum.com/forum/showthread.php?t=66001

Main issues is controller. They are defective and go bad. Make sure you replace it with new part number.

 

[SLCHOE]

So, I did not have a DTC but bought the part anyway and it fixed the problem, at least part of it. Took me less time than I thought, the only midly frusting part was getting the upper passenger side plastic piece back into place (couldn't see where the snaps needed to line up).

Now I get heat from the ceiling vents but not the floor vents. There is no air coming from the floor vents, regardless of which setting I have the rear vents set to.

You wouldn't be able to pull the codes without an OEM level scan tool (BCM).

Seems like you fixed the blend door actuator but now have a ducting issue. Now it sounds lke you have a mode door issue (vent/floor).