K 1500 Yukon XL 4WD V8-8.1L VIN G (2001)
Control Assembly: Description and Operation
HVAC Systems - Automatic
Heater Mode-Auxiliary
Utility vehicles with automatic front and auxiliary HVAC systems will communicate back and forth over Keyboard Data Display (KDD) circuits. The
HVAC control module will send out a HZ signal over the driver HVAC control assembly clock signal circuit to the rear auxiliary HVAC control
assembly & return a HZ signal on the driver HVAC control assembly signal circuit. Utility vehicles with the sunroof option will have the rear auxiliary
HVAC control assembly removed. A manually operated auxiliary system will be installed instead. Yukon and Tahoe models will have an adapter harness
installed in line due to vehicle length.
A/C Mode - Auxiliary
Utility vehicles with automatic front and auxiliary HVAC systems will communicate back and forth over Keyboard Data Display (KDD) circuits. The
HVAC control module will send out a HZ signal over the driver HVAC control assembly clock signal circuit to the rear auxiliary HVAC control
assembly & return a HZ signal on the driver HVAC control assembly signal circuit. Utilities vehicles with the sunroof option will have the rear auxiliary
HVAC control assembly removed. A manually operated auxiliary system will be installed instead. Yukon and Tahoe models will have an adapter harness
installed in line due to vehicle length.