4x4JIA

Hello,
I drive an '03 Burb 1500 4x4 and it started having problems with the air temp on the Driver's side, randomly turning very hot while the air blowing on the PAX side remains blowing cold. Cycling it On & Off does not solve anything but turning the ignition off for 10 - 15 minutes resets the system to blow cold air again. It would work fine for days and suddenly it would go back to blowing super hot air on the driver's side. I've researched old threads and found good information about it but different options were presented, but before I start trying different things I would appreciate it if an expert member could clarify some questions for me.
I found threads telling me that:

1. It is a code problem that can be reset to normal by disconnecting the + of the battery for about an hour.

2. It is caused by a recalled wire harness that needs to be replaced, and

3. It is the Vent actuator has gone bad and needs to be replaced.

If the right answer happens to be #1, could anybody provide a detailed procedure to reset the system. I do not have a scanner.

Does answer #2 have any merit?

If #3 is true, and it is a mechanical issue (worn gears) why would it be resolved by cycling the ignition ON & OFF with 10 - 15 minutes wait in between?

Thanks for any assistance.

in2pro

Have you tried the re-calibration procedure?

Make sure A/C is and A/C controls are off.
With the vehicle off open the hood find the HVAC fuse remove and reinstall allow at least 10 seconds before reinstalling.
Start your vehicle at idle only and do not touch HVAC control.
Wait 40 seconds for control module to recalibrate.
This is 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.

4x4JIA

I will try it. Thanks.

4x4JIA

Hello in2pro,
I tried it and the problem persists.
I am going to try disconnecting the battery and have the cables touch for about 1 minute to delete the memory. My only confusion with the instructions is that it is not clear whether the Module recalibrates itself once the engine is started AND the A/C is OFF (and must remain OFF) or if it does it once the A/C is turned back ON after the engine started and then the air must be run without touching anything for 3 minutes.
Can you clarify?

"There are two ways to reset your body control module

Go to the GENERAL ---> Q: What is this?

Remove BOTH battery cables (for the sake of CAUTION remove air bag fuse and wait 5 MINUTES)

Hold both cables together for 1 minute - drains KAM (keep alive memory).

Put everything back together

Start the engine "DO NOT TOUCH ANYTHING FOR 3 MINUTES"
Q: with A/C OFF or ON?

If you have no broken parts - system not default (normal operation).

Sterling_Archer

My dads Chevrolet 2003 truck is having the same problem except its the passenger side that's giving off the heat.

He took it to the Chevrolet dealer and they told him it would cost $800 to fix the issue. They claim its the temperature operator, a part that costs $200 to replace.

Is there any merit to this or are they just trying to pull a fast one?

4x4JIA

Sterling_Archer, let me tell you where I am in this topic.
I started this thread with a question.
Got answer from in2pro about recalibrating.
I first did the recalibration by removing the Fuse for the A/C, starting the engine with the A/C OFF and allow time for recal. Result: it did not improve the problem.
I tried then disconnecting the battery cables, cleaning the connections to the battery terminals and then, I erased the module's memory by rubbing the two battery cables together for at least one minute. I though that the problem was gone because after two days of driving and one 4 hours trip everything was working well.
Suddenly, I stooped to pump gas and two minutes after I left the station, I get hot air again. I stopped, loosened the battery cables and repeated the last procedure. I got cold air for three more minutes and then hot air until my next stop.
I turned the engine off for about 10 minutes and I was able to drive for 6 hours (without turning engine OFF) and the air stayed COLD. I then made a brief stop. A few minutes after restarting, got hot air again.
Conclusion: I still do not know what causes it but I think I need to check my battery because my thought is that if it has not a real good connection and your engine takes more than 2 seconds to crank when you turn the ignition ON, there might be something going on that messes the system up.
I have read a lot of threads where people take their vehicles to the dealers, spend $800-$1200, get a lot of parts changed and the problem is not solved. I am not ready to do that. I will continue to try figuring out how to get the calibration to stick. But that is me. Please continue the thread if you can share additional information . . . or not.
It is an old problem. I could see that it is endemic in Chevys, GMs and other brothers and cousins and it started around 1997. It's a shame that no solution has been out. It just allows dealers get richer by doing "repairs" that don't work.

kevinkpk

2004 GMC: SUBURBAN..LEFT SIDE AC HOT & RIGHT SIDE COLD, UNABLE..STAYS - JustAn