2003 GMC Sierra 1500 Pickup Owner's Manual - Page 135

Shifting Out of Park (P) If your vehicle has an automatic transmission shift lock control system, you have to fully apply your regular brakes before you can shift from PARK (P) when the ignition is in RUN. See Automatic Transmission Operation on page 2-26. If you cannot shift out of PARK (P), ease pressure on the shift lever and push the shift lever all the way up into PARK (P) as you maintain brake application. Then, move the shift lever into the gear you want. If you ever hold the brake pedal down but still can't shift out of PARK (P), try this: 1. Turn the key to LOCK. 2. Apply and hold the brake until the end of Step 4. Par'-'ng Your Yehi-'e Shifting the transfer case to NEUTRAL can cause your vehicle to roll even if the manual transmission is in gear. Your or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in NEUTRAL. See "Parking Brake" in the Index. Before you get out of your vehicle, move the shift lever into REVERSE (R), and firmly apply the parking brake. Once the shift lever has been placed into REVERSE (R) with the clutch pedal pressed in, you can turn the ignition key to LOCK, remove the key and release the clutch. If you are parking on a hill, or if you are pulling a trailer, see Towing a Trailer on page 4-66. 3. Shift the vehicle to NEUTRAL (N). 4. Start the vehicle and then shift to the drive gear you want. 5. Have the system fixed as soon as you can. 2-48