This information applies to 2008 Enclave and H2, 2007-08 Escalade, Avalanche, Silverado, Suburban, Tahoe, Acadia, Sierra, Yukon, and OUTLOOK with RPO CJ2.
The auto HVAC system may default
to full hot or full cold. There may be any of the following HVAC DTCs: B0423,
B0228, B3779, B0413, B3782, or B0433. This condition may correct itself if the
ignition key is cycled. This condition may be caused by an HVAC system
calibration issue.
Reprogram the HVAC Control Module with the lastest calibrations available from TIS2WEB. Be sure your Tech 2 is updated with the latest software version. After programming, turn the ignition key off, open and close the driver door to turn off RAP and wait one minute. Cycle the ignition key on and clear DTCs. If any DTCs return, perform normal diagnostics using SI procedures.
- Thanks to Jim WillÂ
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