| Subject: | Various HVAC Concerns and DTCs |
| Models: | 2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT |
| 2003-2006 Chevrolet Avalanche, Suburban, Tahoe |
| 2003-2007 Chevrolet Silverado Classic |
| 2003-2007 GMC Sierra Classic |
| 2003-2006 GMC Yukon and Yukon Denali Models |
This PI has been revised to update the model years. Please discard PIT3504B.
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 B0414, B0424, B3770, B0418, B0408, B0263, B0268, and/or B0229 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 connectors C4, C5, and C8 (Document ID # 1562972) 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.
