2006 GMC Envoy Owner's Manual - Page 172

Rear Climate Control System Regular Wheelbase Your vehicle has one of the following rear climate control systems. With either of these systems, the rear climate controls will be disabled when the front climate control system is in defrost. This occurs to provide maximum airflow to clear the windshield. The temperature of the air coming through the rear outlets is determined by the front passenger's temperature setting. Press the PWR button to turn the rear climate controls on and off. Use the mode knob to change the direction of airflow (upper, bi-level or floor) to the rear seat area. H (Panel): When panel mode is selected, the rear system will distribute air from the four headliner outlets. ) (Bi-level): When bi-level mode is selected, the rear system will distribute air from the four headliner outlets, the second seat side floor outlets, and the third seat floor outlet. 6 (Floor): When floor mode is selected, the rear system will distribute air from the second seat side floor outlets and the third seat floor outlet. 3-28