GMC Repair Questions? Ask a Mechanic for Answers ASAP
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
Subject:Intermittent Ticking Noise from I/P, Poor A/C Performance, HVAC DTCs B0229, B0414, B0424, B3770 (Reprogram HVAC Control Module)
Models:2004-2006 Cadillac Escalade Models2004-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe2004-2006 GMC Sierra Models, Yukon Models
with Air Conditioning (RPOs CJ2, CJ3)
Some customers may comment on one or more of the following concerns:
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.
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.