1996 GMC Sonoma Owner's Manual - Page 63

It is dangerous to get out your vehicle if the of shift lever is not fully in PARK (P) with the parking brake firmlyset. Your vehiclecan roll. Don't leave yourvehicle when the engine is running unlessyou have to. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. be sure your To vehicle won't move, even when you'reon fairly level ground, always set your parking brake and move the shift lever to PARK (P). 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 caseis in NEUTRAL (N). be sure the transfer case is in So, a drive gear, two-wheel high(2HI) or four-wheel high (4HI) or four-wheel (4LO) not in low NEUTRAL (N). See "Shifting IntoPARK (P)" in the Index. If you're pulling a trailer, "Towing see a Trailer" in the Index. Ensure the shift lever is fully in PARK (P) range before starting the engine. Your vehicle has a brake-transmission shift interlock. You have to fully apply your regular brakes before you can shift from PARK (P) when the ignition key is in the RUN position. I f you cannot shift out of PARK (P), ease pressure on the shift lever -- push the shift lever all the way into PARK (P) as you maintain brake application. Then move the shift lever into the gear you wish. See "Shifting Out of PARK (P)" in the Index. REVERSE (R): Use this gear to back up. I NOTICE: -- -- -- I ~~~ Shifting to REVERSE (R) while your vehicle is moving forward could damage your transmission. 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 "Stuck in Sand, Mud, Ice or Snow" in the Index. 2-15