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 |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
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.
Recommendation/Instructions:
Check the I/P junction block (Document ID # 1562972) connectors (C4 & C5 on 2007 models) or (X4 & X5 on 2008 models) for poor terminal tension, backed out terminals or connectors not fully seated.
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.