2005 Suburban A/c Blows Hot On Driver's Side.
Posted 15 July 2009 - 08:19 PM
My wife and I just bought a 2005 Suburban last week. The battery was the original, so I swapped it out last Sunday. Pretty easy thing to do, but now we have problems. We have digital dual climate control, and the driver side is blowing hot air. The passenger, and rear are working fine. I have done alot of research and have come to the conclusion it may be the blend door actuator. I have followed some "re start" (remove HVAC/ECAS fuse) procedures and it seems to calibrate and starts blowing cold air, but ends up blowing hot.
The questions I have are as follows. What I don't understand is it was working just fine, until I swapped batteries. How can it all of a sudden be "faulty"?
I have seen the diagrams to remove and replace the actuator, and the re-calibration steps. What I need is clarification on something. Is the HVAC Control Module the same as the blend door actuator? If I replace the blend door actuator what do I have to reset it?
Posted 15 July 2009 - 09:24 PM
Then start the vehicle and don't touch the A/C controls for 1 minute...
Other than the above and if no one else has any things to try, best to get a GM factory service manual set for these types of problems (order from GM dealer of helminc.com).
This would have detailed troubleshooting instructions and instructions for replacing parts if necessary. Some of these things need to be replaced in a certain "sequence" so things are "synchronized".
Posted 15 July 2009 - 09:34 PM
Posted 15 July 2009 - 10:10 PM
Generally an HVAC control module would be an electronic control unit. In newer vehicles this would be a computer module with its own diagnostic codes and would be able to communicate with other computer modules in the vehicle over a computer "local area network".
With those in the newer vehicles, a GM dealer can connect to the vehicle and read diagnostic information for these various computer modules. You need a special scan tool for this.
Then a door module so far as A/C goes is a electric motor basically which would move a door (damper) open, closed, or anywhere in-between.
And with an automatic dual temperature system, there would be all sorts of little electrically operated doors which control this and that.
And these are probably not "smart" doors/motors. The computer may be working "blind" to control them. They need to start out at a set position, then the computer would tell the door to move so far a certain direction. The computer would have no idea where the door actually was or if in fact it moved to where it should have.
So that is why the calibration is important above. The computer may tell all of these electric doors to move all the way one direction. It then would "know" where they are all located and then be able to adjust them as directed.
For example a door (damper) might be able to move to open, middle, or closed.
And the computer could control it to move to open middle or closed.
But say the door is at the middle.
And the computer thinks it is at open.
Then the computer gets a command to move the door to middle and it moves it to closed instead! (Not knowing any better!)
Posted 05 August 2009 - 01:57 AM
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