2011 Chevrolet Impala Owner's Manual - Page 234

9-26 Driving and Operating Make sure the shift lever is fully in P (Park) before starting the engine. The vehicle has an automatic transmission shift lock control system. You must fully apply the brakes first, then press the shift lever button before you can shift from P (Park) while the ignition is in ON/RUN. If you cannot shift out of P (Park), ease pressure on the shift lever and push the shift lever all the way into P (Park) as you maintain brake application. Then press the shift lever button and move the shift lever into another gear. See Shifting Out of Park on page 9‑23. R (Reverse): Use this gear to back up. Notice: Shifting to R (Reverse) while the vehicle is moving forward could damage the transmission. The repairs would not be covered by the vehicle warranty. Shift to R (Reverse) only after the vehicle is stopped. To rock the vehicle back and forth to get out of snow, ice, or sand without damaging the transmission, see If the Vehicle is Stuck on page 9‑11. N (Neutral): In this position, the engine does not connect with the wheels. To restart the engine when the vehicle is already moving, use N (Neutral) only. Also, use N (Neutral) when the vehicle is being towed. There are several different positions for the shift lever. P (Park): This position locks the front wheels. It is the best position to use when the engine is started because the vehicle cannot move easily. { WARNING It can be dangerous to get out of the vehicle if the shift lever is not fully in P (Park) with the parking brake firmly set. The vehicle can roll. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure the vehicle will not move, even when you are on fairly level ground, use the steps that follow. If you are pulling a trailer, see Driving Characteristics and Towing Tips on page 9‑42. { WARNING Shifting into a drive gear while the engine is running at high speed is dangerous. Unless your foot is firmly on the brake pedal, the vehicle could move very rapidly. You could lose control and hit people or objects. Do not shift into a drive gear while the engine is running at high speed.