AC Blend door actuators functions

[Cthom]

2015 Yukon Denali XL
can someone tell me the functions of the three AC blend door actuators in the vehicle. To my understand theres one (i think) under the driver side and two passager side one upper and one lower.

driver side _______
passager side upper ________
passager side lower _________

 

[OR VietVet]

Not sure about yours but mine has 4 actuators. I also have rear a/c and heat and auto temp control.
1. Air direction door at d/s above gas pedal.
2. D/s hot/cold control is under dash above transmission hump.
3. P/s hot/cold control is under the upper dash cover on top of htr-a/c box toward center and next to heater core.
4. Recirc actuator is on top of a/c box on far right and close to firewall.

 

[Cthom]

Not sure about yours but mine has 4 actuators. I also have rear a/c and heat and auto temp control.
1. Air direction door at d/s above gas pedal.
2. D/s hot/cold control is under dash above transmission hump.
3. P/s hot/cold control is under the upper dash cover on top of htr-a/c box toward center and next to heater core.
4. Recirc actuator is on top of a/c box on far right and close to firewall.

yes i have rear A/c heat and temp controls.
the issue im having is the AC is blowing cold in the rear but warm in the front when the temp is sync or Lo

 

[Fless]

I'm sure @swathdiver or @Doubeleive could enlighten us...

 

[Doubeleive]

needs a scan to determine what is being commanded -vs-actual, that might also entail a visual inspection to confirm position.
it could be a actuator or could be one of the ambient air sensors is goofy, I would suspect maybe the rear one if equipped
any previous work done or part being replaced?

a scanner should be used, otherwise it's a guess and throwing parts at it can add up

 

[Joseph Garcia]

Yes, the use of a quality bi-directional scanner would be extremely helpful in diagnosing your issue. There are specific tests that you can run on those actuators.

 

[swathdiver]

2015 Yukon Denali XL
can someone tell me the functions of the three AC blend door actuators in the vehicle. To my understand theres one (i think) under the driver side and two passager side one upper and one lower.

driver side _______
passager side upper ________
passager side lower _________

Driver's Footwell is the Mode Actuator and controls where the air is going, defrost, feet, bi-level, etc.

Passenger Footwell is the driver's side temperature actuator that controls the temperature of the air coming out of the vents on that side.

Passenger Upper - there are two up here. One is the passenger side temperature actuator, aka, blend door, and the other of the Recirc or fresh air actuator.

There are two more in the rear on the passenger side. One functions as a mode actuator and the other as temperature control.