This 2003 GMC Envoy came in with the complaint that the a/c will only blow out the defrost and floor. Not through the dash vents. I checked codes and found a code B0263 for a fault with the mode actuator. I first ran into this problem after changing a battery in one of these vehicles last year. Whenever the battery is disconnected the HVAC unit will perform a recalibration of all doors. This causes the door motors to be moved full cycle and the mode door will stick some times. I now hook a jump box to the system before changing the battery in Trailblazers or Envoys to prevent a recalibration from occurring. This way I will not be blamed for a stuck actuator motor.
Anyways to change the actuator motor, first drop the hush panel under the driver’s side of the dash. There are some parts that have to be disconnected from the panel including the turn signal flasher assembly shown in the next picture.
Next, I removed the lower dash knee panel to have a little more room to work.
I had to pull a push pin retainer out at the left side of the duct work in order to remove the driver’s floor vent.
Now, I could finally see the actuator on the side of the heater a/c box.
I removed the actuator and installed the new one. Performed a recalibration with my Tech 2 and put all the panels back in place. A recalibration can be done by disconnecting the battery for at least one minute, reconnect the battery, start the engine and leave the a/c controls alone. I would recommend letting the engine run for at least two minutes, turn the ignition off for at least ten seconds but no more than thirty seconds and then restart the engine so that confirmation of the repair can be done.
I do not recommend connecting the wiring to the actuator until it is installed. They come prepositioned for easier installation.
The notch at the lower edge of the gear is an alignment point. There is a corresponding tab on the door linkage that needs to be lined up with this notch.
To purchase the mode valve actuator, please click here. To see updated information about actuator positions and alignment, please click here.
The wrong one has been changed. The correct unit is behind the driver’s side of the dash, near the rear of the radio and a/c control head. Please reread the post and look closely at the pictures for actuator location.
the old part # is 52402612/010040281c the new one is 52411434/010100762A
they did not connect the actuator without it being mounted, I did the recalibration after I got it home because it didn’t work. when I did the recalibration I could see the outside circle move,after that did not work I hooked up the old one they left in the car to see what it would do and it moved the full range that the recalibration wanted it to. this one is located just to the left of the glove box
I have a 2004 Envoy, and was excited to see there was an answer to the problem.. so I had a new one installed and it did not work? could the new one also be locked up,or maybe the wiring harness. The first guy replaced the entire control unit. I am getting deep into this for what seems to be a small problem
Yes, it is . The same part and the same procedure.
Just replaced the battery. All other vents: flooor, and 2nd and 3rd row seats are working fine except EXCEPT dash vents. Is this the same for a 2004 Envoy XL with dual climate control?