Air Distribution: Notes

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The HVAC control assembly controls the distribution of air by the use of a defrost actuator and a mode actuator. The modes that may be selected are:

DEFROST
DEFOG
PANEL
BI-LEVEL
FLOOR

The mode actuator is connected to the mode door by a cam type linkage system. Depending on the position of the door, air is directed through the HVAC module and distributed through various ducts leading to the outlets in the dash. If the HVAC control assembly detects a fault with the mode door, the HVAC control assembly will try to drive the actuator for a predetermined amount of time to DEFROST, which is the defaulted position for the mode door actuator. When the mode switch is placed in the DEFROST or DEFOG positions the A/C is commanded on and the recirculation door is moved to the outside air position to help reduce window fogging. A/C is available in all modes and RECIRCULATION is only available in the PANEL and BI-LEVEL modes.