2003 GMC Yukon Rear HVAC issue

[Saucy_Walnuts]

My 2003 GMC Yukon rear HVAC is stuck on heat. Ive cleaned the control know on the overhead console, and put a new actuator. Still nothing. The blend door is working properly when I manually move it between heat and air. Do the rear HVAC need to relearn like the front does? I do have the digital front HVAC controls. Im at a loss. Ive been dealing with it during the summer by manually leaving it at AC for the rear but I would like to have working controls. The actuator for the rear floor/overhead works fine. Any input or ideas would be grateful.

 

[Joseph Garcia]

I believe that a relearn procedure is needed.

@swathdiver can add some perspective here regarding your issue.

 

[swathdiver]

My 2003 GMC Yukon rear HVAC is stuck on heat. Ive cleaned the control know on the overhead console, and put a new actuator. Still nothing. The blend door is working properly when I manually move it between heat and air. Do the rear HVAC need to relearn like the front does? I do have the digital front HVAC controls. Im at a loss. Ive been dealing with it during the summer by manually leaving it at AC for the rear but I would like to have working controls. The actuator for the rear floor/overhead works fine. Any input or ideas would be grateful.

Proper diagnostics with a bi-directional scan tool that can see internal BCM codes and work with the actuators would be great here.

Yes, the actuators always need to be calibrated but there have been exceptions. Some fellas report success by doing it manually. It's never worked that way for me, always had to use the Tech-2.

 

[Saucy_Walnuts]

Proper diagnostics with a bi-directional scan tool that can see internal BCM codes and work with the actuators would be great here.

Yes, the actuators always need to be calibrated but there have been exceptions. Some fellas report success by doing it manually. It's never worked that way for me, always had to use the Tech-2.

Ah ok. I did try pulling the fuse and putting it back in but did not work. I'll see if I can find a new or used HVAC control module.

 

[Saucy_Walnuts]

So continuing on with this. I had found a new module. It works. Went through the reset procedure,by pulling the files while truck is off for 30 seconds. Re inserted them, put it on heat and fan setting lowest. It did the test successfully. Both The actuators moved both directions then rested in position. But now instead of being stuck on heat it is stuck on AC now. Could it be a actual control know issue by the visor and sunroof? It has auto/auxiliary controls as well. Im stumped at this point. I did check voltagees as well. All are good. Which is leading me to the actual control knobs. Its getting old manually moving them back and forth. For heat or air. Any further input would be greatly appreciated.

 

[Saucy_Walnuts]

Here is the module I got.