Rear blend actuators removal instructions needed

Tiny
TNHARLEY
  • MEMBER
  • 2011 CHEVROLET TAHOE
  • 5.3L
  • V8
  • 2WD
  • AUTOMATIC
  • 137,000 MILES
Got an issue where air not coming out of four roof vents. Research tends to indicate blend actuator and I have a buddy in parts that will sell it to me for his employee cost. Already got paneling remover but OMG, they are behind the HVAC unit. What in the world?

How in the heck are you supposed to do this?
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Friday, June 28th, 2019 AT 7:45 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome to 2CarPros.

Actually, the blend actuator is to determine temperature which enters the vehicle. I believe you have a problem with what is called a mode door actuator. That is what determines where the air flow exits.

Now, I don't know if you have automatic climate control or manual, so I am going to include directions for the mode valve actuator replacement for both. All attached pictures correlate with the directions.

_____________________________

Manual HVAC

See pics 1 and 2 for location and directions.

____________________________

Auto HVAC

See Pics 3 and 4 for location and directions.

____________________________

Here are the directions for recalibration of the automatic HVAC. You can do it with a scanner or without.

HVAC - AUTOMATIC
Actuator Recalibration

When replacing the HVAC control module it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC control module be sure to perform the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

1. Place the ignition switch to the OFF position.
2. Disconnect the scan tool.
3. Install the HVAC control module.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. Wait 40 seconds for the HVAC control module to self-calibrate.
7. Verify that no DTCs have set as current DTCs.

When replacing the HVAC actuator it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC actuator be sure to perform one of the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Preferred Method (w/Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch in the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. With the scan tool, initiate the Motor Re-calibration feature of the Heating and Air Conditioning Special Functions menu.
7. Verify that no DTCs have set as current DTCs.

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Alternate Method (w/o Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch to the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
6. Install the HVAC/ECAS fuse.
7. Start the vehicle.
8. Wait 40 seconds for the HVAC control module to self-calibrate.
9. Verify that no DTCs have set as current DTCs.

______________________________

Manual HVAC

HVAC - MANUAL
Actuator Recalibration

When replacing the HVAC control module it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC control module be sure to perform the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

1. Place the ignition switch to the OFF position.
2. Disconnect the scan tool.
3. Install the HVAC control module.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. Wait 40 seconds for the HVAC control module to self-calibrate.
7. Verify that no DTCs have set as current DTCs.

When replacing the HVAC actuator it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC actuator be sure to perform one of the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Preferred Method (w/ Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch in the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. With the scan tool, initiate the Motor Re-calibration feature of the Heating and Air Conditioning Special Functions menu.
7. Verify that no DTCs have set as current DTCs.

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Alternate Method (w/o Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch to the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
6. Install the HVAC/ECAS fuse.
7. Start the vehicle.
8. Wait 40 seconds for the HVAC control module to self-calibrate.
9. Verify that no DTCs have set as current DTCs.

______________________________
Let me know if this helps or if you have other questions.

Take care,
Joe
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Friday, June 28th, 2019 AT 8:34 PM
Tiny
TNHARLEY
  • MEMBER
Thank you for the reply. I believe you are correct in that it is the mode door actuator but fortunately it s the same replacement part.

My issue (which is the same experience by user jeff_wrenchonit in this thread https://www.2carpros.com/questions/how-to-replace-rear-hvac-blend-door-actuator) is the pictures show the actuator attached to the front of the unit and thus easily accessible. Unfortunately that s not where the ones on my truck are located. They are behind the unit (in the side of rear quarter panel). so when looking at the until normal you don t even see them. Being that there is a screw that has to be removed and one essentially sits above the other, i have no idea how to get to it.
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Saturday, June 29th, 2019 AT 4:04 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:

I have never had one like that. However, lets get through this together. I looked at the above link and identified the manufacturer. I had to use a different manual to even find it. Now, (and don't laugh) I had to put what they said are the directions in picture form. The first three is everything they provided. I have a feeling that you will laugh at them.

Next, I looked closely at the pic. I circled what I believe to be two screws at the top and at the bottom, I circled what I believe to be posts that are in rubber grommets. Once the screws are out, it looks like that would pull up.

Now to add insult to injury, this model also shows the mode actuator on the front. Since your's is different, make sure the pic looks like what you have. I noted that the vent to the ceiling is above the actuator in the pic.

Let me know if any of this helps. I wish I was there. It would be much easier. LOL

Take care,
Joe
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Saturday, June 29th, 2019 AT 6:54 PM

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