Removal Procedure

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Remove the auxiliary HVAC module (3) from the vehicle. Refer to HVAC MODULE REPLACEMENT - AUXILIARY (SUBURBAN/YUKON XL) or HVAC MODULE REPLACEMENT - AUXILIARY (TAHOE/YUKON) .

Fig 1: Removing Auxiliary HVAC Module From Vehicle
Courtesy of GENERAL MOTORS CORP.
Remove the air temperature actuator (1) from the auxiliary HVAC module.

Fig 2: Removing Air Temperature Actuator From Auxiliary HVAC Module
Courtesy of GENERAL MOTORS CORP.
Remove the stud on the underside of the auxiliary HVAC module between the heater core inlet and outlet pipes.
Carefully separate the heater core pipe gasket from the module case and remove the heater core pipe retainer.
Remove the auxiliary HVAC module lower cover.

Fig 3: Removing Auxiliary HVAC Module Lower Cover
Courtesy of GENERAL MOTORS CORP.
Remove the heater core clamp.
Remove the heater core from the auxiliary HVAC module.

Fig 4: Removing Heater Core From Auxiliary HVAC Module
Courtesy of GENERAL MOTORS CORP.