GM Service Manual Online
For 1990-2009 cars only

Rear HVAC System May Come On Unexpectedly

Subject:Rear HVAC System May come On Unexpectedly

Models:2007-2008 Chevrolet Suburban, Tahoe
2007-2008 GMC Yukon, Yukon XL
Equipped With Manual HVAC (RPO CJ3)



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

The Rear HVAC system may come on unexpectedly. This condition may occur on vehicles equipped with a Front Manual HVAC controlled system (RPO CJ3) combined with a Rear Manual HVAC control (non- Rear Seat Audio). This concern is most likely to occur when the Rear HVAC control knobs are placed "in-between detents".

Recommendation/Instructions:

To correct this condition, program the HVAC control module with the latest software calibrations.

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.