Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET2007SILVERADO CLASSIC 1500 2WD V8-6.0LREPAIR AND DIAGNOSISTECHNICAL SERVICE BULLETINSALL TECHNICAL SERVICE BULLETINSA/C - HVAC CONTROL MODULE LOCKUP DURING REPROGRAMMING
2007 Chevrolet Silverado Classic 1500 2WD V8-6.0L
A/C - HVAC Control Module Lockup During Reprogramming
2007 Chevrolet Silverado Classic 1500 2WD V8-6.0LSECTION A/C - HVAC Control Module Lockup During Reprogramming
Bulletin No.: 06-01-39-014
Date: December 06, 2006
INFORMATION
Subject:
Information On HVAC Control Module Lockup During Reprogramming
Models:
2007 Cadillac Escalade Models
2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007 GMC Sierra, Yukon Models
with Automatic Temperature Control HVAC System (RPO CJ2)
The purpose of this bulletin is to alert technicians to a condition they may encounter while trying to reprogram a Heating, Ventilation and Air Conditioning (HVAC) control module. If the HVAC control module reprogramming event is interrupted, the control module may go into a "lock up" mode. This will cause the HVAC control module to disable communications and a second try at reprogramming will fail. The interruption may be caused by a software anomaly inside the HVAC control module.
If the HVAC reprogramming event was interrupted and a subsequent reprogramming attempt fails, perform a battery reset. This can be accomplished by either removing and reinstalling the HVAC BATT fuse, located in the underhood fuse block, or by disconnecting and reconnecting the HVAC control module connector C2. Connector C2 is grey in color with 16 cavities. Once the battery reset has been performed, the HVAC control module will resume communications and will then be able to be reprogrammed.
The Warranty Parts Center (WPC) has received HVAC control modules that have been returned and described as non-functional but were tested with no problems found. If the module has been replaced due to a failed second attempt at reprogramming caused by the lock up, the module will be returned and charged back to the dealer. Technicians must also remember that after a new HVAC control module has been installed into a vehicle, it must be programmed, otherwise it will not be functional.
Disclaimer
Date: December 06, 2006
INFORMATION
Subject:
Information On HVAC Control Module Lockup During Reprogramming
Models:
2007 Cadillac Escalade Models
2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007 GMC Sierra, Yukon Models
with Automatic Temperature Control HVAC System (RPO CJ2)
The purpose of this bulletin is to alert technicians to a condition they may encounter while trying to reprogram a Heating, Ventilation and Air Conditioning (HVAC) control module. If the HVAC control module reprogramming event is interrupted, the control module may go into a "lock up" mode. This will cause the HVAC control module to disable communications and a second try at reprogramming will fail. The interruption may be caused by a software anomaly inside the HVAC control module.
If the HVAC reprogramming event was interrupted and a subsequent reprogramming attempt fails, perform a battery reset. This can be accomplished by either removing and reinstalling the HVAC BATT fuse, located in the underhood fuse block, or by disconnecting and reconnecting the HVAC control module connector C2. Connector C2 is grey in color with 16 cavities. Once the battery reset has been performed, the HVAC control module will resume communications and will then be able to be reprogrammed.
The Warranty Parts Center (WPC) has received HVAC control modules that have been returned and described as non-functional but were tested with no problems found. If the module has been replaced due to a failed second attempt at reprogramming caused by the lock up, the module will be returned and charged back to the dealer. Technicians must also remember that after a new HVAC control module has been installed into a vehicle, it must be programmed, otherwise it will not be functional.
Disclaimer
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.