2006 GMC Envoy Owner's Manual - Page 105

REVERSE (R): Use this gear to back up. {CAUTION: If you have four-wheel drive, your vehicle will be free to roll - even if your shift lever is in PARK (P) - if your transfer case is in NEUTRAL. So, be sure the transfer case is in a drive gear - not in NEUTRAL. See Four-Wheel Drive on page 2-27. See Shifting Into Park (P) on page 2-32. Ensure the shift lever is fully in PARK (P) before starting the engine. Your vehicle has an automatic transmission shift lock control system. You have to fully apply the regular brakes before you can shift from PARK (P) when the ignition key is in RUN. If you cannot shift out of PARK (P), ease pressure on the shift lever, press the button on the shift lever and push the shift lever all the way into PARK (P) as you maintain brake application. Move the shift lever into the gear you wish. See Shifting Out of Park (P) on page 2-33. Notice: Shifting to REVERSE (R) while your vehicle is moving forward could damage the transmission. The repairs would not be covered by your warranty. Shift to REVERSE (R) only after your vehicle is stopped. To rock your vehicle back and forth to get out of snow, ice, or sand without damaging your transmission, see If Your Vehicle is Stuck in Sand, Mud, Ice, or Snow on page 4-44. NEUTRAL (N): In this position, the engine does not connect with the wheels. To restart when you are already moving, use NEUTRAL (N) only. {CAUTION: Shifting into a drive gear while your engine is running at high speed is dangerous. Unless your foot is firmly on the brake pedal, your vehicle could move very rapidly. You could lose control and hit people or objects. Do not shift into a drive gear while your engine is running at high speed. 2-25