| Subject: | Repeat HVAC Actuator Replacements |
| Models: | 2003-2007 HUMMER H2, SUT |
| 1999-2007 Chevrolet Silverado Classic |
| 1999 -2007 GMC Serria Classic |
| 2002-2006 Cadillac Escalade, ESV, EXT |
| 2000-2006 Chevrolet Avalanche, Suburban, Tahoe |
| 2000-2006 GMC Yukon, Yukon Denali, Yukon XL, Yukon Denali XL |
| 2002-2007 Chevrolet Trailblazer Models |
| 2002-2007 GMC Envoy Models |
| 1998-2004 Chevrolet S/T Classic Blazer and S10 Pickup |
| 1998-2004 GMC S/T Classic Jimmy and Sonoma |
| 1998-2007 Oldsmobile Bravada |
This PI Being Updated To Add Additional Model Years. Please Discard PI02080.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A replacement HVAC actuators is inoperative or that has worked one time and quit. The HVAC control head learns the stopping points based on how far the HVAC DOOR travels. If the actuator reachs the mechanical stops on the back of the actuator it will
be outside of the range that the HVAC control head can learn. If the actuator was not mounted to the HVAC case prior to plugging in its connector, the actuator will go out of range and be inoperative.
Recommendation/Instructions:
Always attach the HVAC actuator to the case before installing the electrical connector.
If an actuator is out of range it may be possible to bring it back into range by following the procedure below:
- Turn ON the ignition, with the engine OFF.
- Connect a 3 amp fused jumper wire between the actuator control circuit and the 5 volt reference circuit of the actuator connector.
- Remove the jumper wire and actuator connector when the actuator is at the center position.
- If the actuator doesn't move in step 2. Try installing the jumper wire from control circuit and the ground circuit of the actuator.
- With the actuator in the center position, install the actuator to the hvac case and secure the mounting screws and then connect the actuator connector.
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.
