2005 Buick Terraza



April, 30, 2009 AT 4:36 PM

Air Conditioning problem
2005 Buick Terraza 6 cyl Front Wheel Drive Automatic 86,000 miles

On the driver's side, when the a/c is on, the air is still HOT.

This is not the case for the passenger side. Nor is it the case for the rear air.

Someone told me that the calibration of the a/c unit shoud first be checked before removing the dash board to determine if the problem is the blend door or something more serious.

The local GM dealer says that it will be a 4 hour job to remove and later replace the dash board -- a $400 labor by itself.

I'm worried.


Rear Door


3 Answers



May, 2, 2009 AT 6:04 AM

Before you take it in try to recalibrate the actuators, with out a scan tool it's done this way: RE-CALIBRATING ACTUATORS 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. Alternate Method (w/o Scan Tool) Clear all DTCs. 1. Place the ignition switch to the OFF position. 2. Connect all previously disconnected components. 3. With the Mode knob in the PANEL position, press and hold the AC button for 5 seconds. 4. Rotate the Mode knob fully counterclockwise. 5. Rotate the Mode knob fully clockwise. 6. Rotate the Mode knob fully counterclockwise. 7. Release the AC button. 8. Wait 40 seconds for the HVAC control module to self-calibrate. 9. Start the vehicle. 10. Verify that no DTCs have set as current DTCs. 11.



May, 17, 2009 AT 7:34 AM

[merlin2021"] Thank you for your input.

I need some more guidance.

I asked the mechanic what he found when he did the diagnostic scan. He said that it showed that there was NOTHING WRONG electronically. He further said that until he removed the dashboard, that he would not be able to determine why the Driver's Side temperature controller could not control the air vent output on the Driver's Side. He couldn't estimate the cost of repair. He did say, though, that if he had to replace "the box", whatever that meant, that the repair cost could be over $1,000.

Currently, it always pumps out only hot air. [Though sometimes/rarely, it seems to work for awhile.]

BTW, the Shop Rate at this dealer repair shop is $100 per hour.

I went to another GM dealer shop out in the country which charges $70 per hour and he said that on a Chrysler product he worked on the previous week, the cost was over $1,300!

I guess that the various mechanics are suggesting that I take out a 2nd mortgage.

I googled Buick Terraza blend door and got a number of websites. Apparently, there is an electronic actuator that controls the blend door. Replacing that would be expensive from what I've heard.

Anyway, if you can give me some guidance regarding cost/complexity of repairing this problem, I would be grateful.




May, 17, 2009 AT 7:44 AM

Has anyone checked the a/c refrigerant level yet? I know on Fords, if it's low this is what happens on Dual zone a/c systems.

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