Subject: | Various HVAC Concerns and DTCs |
Models: | 2007-2008 Cadillac Escalade, ESV, EXT |
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
2007-2008 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL |
2008 Hummer H2 |
RPO C67, CJ3, or CJ2 |
This PI was superseded to update Recommendation/Instructions. Please discard PIT4471.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Owners may comment on various HVAC concerns and DTCs B0228, B0413, B0423, and/or B3779 may be set. Also, complaints of temperature doors defaulting to full hot position or unable to obtain defrost position may occur.
Check the following areas:
If a terminal connection concern is found, please contact Ray Norton at 248-841-3773 to discuss the case in more detail. If you leave a message and do not hear back within 1 hour, do not hold the vehicle and continue with normal repairs.
Thanks for your support.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.