[timberdoodle]

I took my truck to the Stealer today and they downloaded a program change to the heater computer. It changes the position of the door in the heater ducts so that it stops rattling.

 

[Polarbear]

Would you happen to have a bulletin #? Id be interested in reading it.
My 07 has developed something that could be related to this... If i tap the dash just above the radio before it curves down on the passenger side itll go away momentarily, then come back...
I remembered this post so i tried moving the flow know. I noticed it in the defrost/floor mode then move it to just floor and it got quieter. then move to dash/floor and it went away completely. I then moved it back to defrost/floor, but couldnt get it to do it over the course of about 30 miles this morning...

 

[timberdoodle]

I didn't ask because I was complaining about the rattle from the weather strips on the front windshield. The tech got it mixed up with heater program problem. When he said he reprogramed the heater I was not real happy until he explained that it just repositioned the door. Sorry. I have an appointment tomorrow to have the revised strips installed on the front windshied and I will try to find out.

 

[buddygunzz]

Subject: Intermittent Ticking Noise from I/P, Poor A/C Performance, HVAC DTCs B0229, B0414, B0424, B3770, (Reprogram HVAC Control Module) #06-01-38-003 - (04/27/2006)



Models: 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)




--------------------------------------------------------------------------------

Condition
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.

Cause
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.

The following table lists the HVAC system doors and the DTC associated with it.

System Door
Overtravel DTC

Air inlet door (recirculation door)
B0229

Left temperature door
B0414

Right temperature door
B0424

Front system mode door
B3770


Correction
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 A/C system performance concern.