1998 GMC Sonoma Owner's Manual - Page 82

Ensure the shift lever is fully in PARK (P) range before starting the engine. Your vehicle has a Brake-Transmission Shift Interlock (BTSI). You have to fully apply your 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 -- 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. NEUTRAL (N): 111 this position, your engine doesn't connect with the wheels. To restart when you're already moving, use NEUTRAL (N) only. REVERSE (R): Use this gear to back up. Shifting outof PARK (P) or NEUTRAL (N) while your engine is "racing" (running at high speed) is dangerous. Unless your fobt is firmly on the brake pedal, your vehicle could movevery or rapidly. You could lose control and hit people objects. Don't shift out PARK (P) or of NEUTRAL (N) while your engine is racing. Shifting toREVERSE (R) while your vehicle is moving forward could damage your transmission. Shift toREVERSE (R) only after your vehicle is stopped. NOTICE: Damage to your transmission caused shifting by out of PARK (P) or NEUTRAL (N) with the engine racing isn't covered by your warranty. To rock your vehicle back and forth toget out of snow, ice or sand without damaging your transmission, see "Stuck in Sand, Mud, Ice or Snow" in the Index. 2-18