2008 GMC Envoy Owner's Manual - Page 105

Shifting Into Four-Wheel High or Automatic Four-Wheel Drive Turn the knob to Four-Wheel High or Automatic Four-Wheel Drive. This can be done at any speed unless you are shifting out of Four-Wheel Low. The indicator light will flash while shifting. It will remain on when the shift is complete. unless your vehicle is moving less than 2 mph (3.2 km/h) and the transmission is in NEUTRAL (N). After 30 seconds, the transfer case will return to the setting last chosen. Shifting Out of Four-Wheel Low To shift from Four-Wheel Low to Four-Wheel High, Auto Four-Wheel Drive, or Two-Wheel High, your vehicle must be stopped or moving less than 2 mph (3.2 km/h) with the transmission in NEUTRAL (N) and the engine running. The preferred method for shifting out of Four-Wheel Low is to have your vehicle moving 1 or 2 mph (1.6 to 3.2 km/h). Turn the knob to Four-Wheel High, Auto Four-Wheel Drive, or Two-Wheel High. You must wait for the Four-Wheel High, Auto Four-Wheel Drive, or Two-Wheel High indicator light to stop flashing and stay off before shifting your transmission into gear. If the knob is turned to Four Wheel-High, Auto Four-Wheel Drive, or Two-Wheel High when your vehicle is in gear and/or moving, the Four-Wheel High, Auto Four-Wheel Drive, or Two-Wheel High indicator light will flash for 30 seconds. It will not complete the shift unless your vehicle is moving less than 2 mph (3.2 km/h) with the transmission in NEUTRAL (N). Shifting Into Two-Wheel High Turn the knob to Two-Wheel High. This can be done at any speed unless you are shifting out of Four-Wheel Low. Shifting Into Four-Wheel Low To shift to Four-Wheel Low, the vehicle's engine must be running and the vehicle must be stopped or moving less than 2 mph (3.2 km/h) with the transmission in NEUTRAL (N). The preferred method for shifting into Four-Wheel Low is to have your vehicle moving 1 or 2 mph (1.6 to 3.2 km/h). Turn the knob to Four-Wheel Low. You must wait for the Four-Wheel Low indicator light to stop flashing and stay on before shifting the transmission into gear. If you turn the knob to Four-Wheel Low when your vehicle is in gear and/or moving, the Four-Wheel Low indicator light will flash for 30 seconds and not complete the shift 2-31