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Dave Nova
Dave Nova, GMC Technician
Category: GMC
Satisfied Customers: 19450
Experience:  ASE Master Certification. GM World Class Certification
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GMC Yukon: I have a 2004 yukon with heater issues. it has

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I have a 2004 yukon with heater issues. it has the dual temperature controls. drivers side will switch to full heat at random. turning off ignition and restarting usually fixes problem temporarily.
Hello and thank you for trusting me with your question. My name is XXXXX XXXXX I will do my best to help you with your GMC problem.

Don't Forget, the deposit you placed to ask this question is not used to compensate me until you rate my service! Please remember that when you are asked to give a rating, you are rating My Service, and not this website itself or your vehicle.

The symptoms that you are having indicate that the problem is in the temperature actuators themselves. As the actuators wear, the feedback from the actuators goes out of normal limits. This forces the control module into a default mode (full heat) where you lose control over the actuators. You have two options at this point, start replacing actuators or have the control module reprogrammed. GM has developed new software for the a/c control module that opens up the feedback limits for the actuators. This eliminates the problem. You would need to have the dealer reprogram the a/c control module. Most dealers will charge between $60-100 for this reprogramming. This is far cheaper than replacing even one actuator.

Customer: replied 4 years ago.

There does seem to be a lot of discussion on the web about heater problems similar to mine. This fix almost seems too good to be true. How confident are you and would more specific info from me help?

I will gladly make an appointment at my dealer if we are reasonably sure. Thanks.

I am very confident that this will fix your problem. It is a very common issue and GM published a service bulletin concerning the reprogramming to fix the issue. When speaking with your dealer, refer to bulletin # 06-01-38-003. I have included it below for you as well.

Bulletin No.: 06-01-38-003

Date: April 27, 2006


Intermittent Ticking Noise from I/P, Poor A/C Performance, HVAC DTCs B0229, B0414, B0424, B3770 (Reprogram HVAC Control Module)


2004-2006 Cadillac Escalade Models
2004-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2004-2006 GMC Sierra Models, Yukon Models


with Air Conditioning (RPOs CJ2, CJ3)


Some customers may comment on one or more of the following concerns:

^Intermittent ticking/clicking noise from the instrument panel.


^Recirculation mode does not work or Air Conditioning (A/C) system performance is poor during high ambient temperatures.


^Unable to control the driver side temperature.


^Unable to control the passenger side temperature.


^Unable to change the front system modes.



This condition may be caused by the Heating, Ventilation and Air Conditioning (HVAC) actuators that may hunt for the correct commanded position. This cycling may cause a clicking or ticking noise.

An overtravel of the HVAC system control doors may cause one or more of the concerns listed above. If an overtravel occurs, a Diagnostic Trouble Code (DTC) will be set, and the door will go to a preset default position. When a system door defaults, that door will stay at the default position until the DTC is cleared. After the DTC is cleared, the door will operate properly until the overtravel condition re-occurs.


Technicians are to perform the normal diagnostic procedures in SI for these concerns. If diagnostics show that the HVAC system door(s) travel below 5 counts (out of the lower range) or above 250 counts (out of the upper range), then update the software calibrations in the HVAC control module. The new calibrations were made available to dealerships as part of TIS2000 incremental satellite update version 2.5, which was broadcast to dealers in February 2006.

The new calibrations have been updated to compensate for the actuator overtravel condition, the actuator hunting and the ticking/clicking noises. The new calibrations effectively eliminate the codes listed above, the default position of the doors associated with the DTCs and opens up the feedback position value. The new calibrations should not be used unless the vehicle has one or more of the customer concerns listed above or a DTC listed above has been set. The new calibrations will not correct any other DTC or NC system performance concern.



Dave Nova and other GMC Specialists are ready to help you

I noticed you requested a refund on the question. Did you need more help with this problem?

Customer: replied 4 years ago.

The $90 reprogramming per the TSB did not fix the problem. The GMC dealer replaced the heater blend actuator for another $375. So far (2 days) it seems to be working. I did not want to spend that kind of money right now to fix it, but once it was in the shop it pretty much had to be done.

It was unfortunate that the reprogramming did not fix the problem. 99% of the time reprogramming fixes these concerns, the other 1% have to get the actuator replaced. These actuators cost about $100 from the aftermarket and take about 20 minutes to replace. If you would have replied back to me, I could have saved you some money. Glad you got the problem solved though.

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