Clarification of HVAC Module and Locations Descriptions - Not Clear in SI - keywords AC actuator air blower cold control head hot RSA

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

Additional Clarification of HVAC modules and location descriptions in SI.

There are 4 HVAC control modules on these vehicles.

1. HVAC Control module- Located in front IP panel near radio. You can communicate with the HVAC control module via class II under heating and air conditioning.
2. HVAC Control Assembly- Front Auxiliary - (control head) - Located above the rear view mirror. Cannot communicate on Class II. Provides driver requests for rear operation via dedicated circuit inputs to HVAC Control Module-Auxiliary.
3. Rear Seat Audio controller (control head) - Located in the rear of center console you can communicate with the RSA/HVAC module with the Tech 2 under Rear HVAC. Communicates via Class II to other modules.
4. HVAC Control Module - Auxiliary (programmer) - Located on the rear HVAC case behind quarter trim. Use Document ID # 899666 to see illustration. You can communicate with the Auxiliary HVAC Control Module with the Tech 2 under Rear Aux. Climate Module. Receives requests via Class II and discrete inputs. Provides direct output to rear HVAC control devices (actuators, blower module).

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.