2011 GMC Acadia Owner's Manual - Page 290

9-18 Driving and Operating Notice: Using a tool to force the key to turn in the ignition could cause damage to the switch or break the key. Use the correct key, make sure it is all the way in, and turn it only with your hand. If the key cannot be turned by hand, see your dealer. In an emergency: 1. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This may deplete power assist, requiring increased brake pedal force. 2. Shift the vehicle to N (Neutral). This can be done while the vehicle is moving. After shifting to N (Neutral), firmly apply the brakes and steer the vehicle to a safe location. 3. Come to a complete stop, shift to P (Park), and turn the ignition to LOCK/OFF. On vehicles with an automatic transmission, the shift lever must be in P (Park) to turn the ignition switch to the LOCK/OFF position. 4. Set the parking brake. See Parking Brake on page 9‑30. Ignition Positions ( (STOPPING THE ENGINE/ LOCK/OFF): When the vehicle is stopped, turn the ignition switch to LOCK/OFF to turn the engine off. Retained Accessory Power (RAP) will remain active. See Retained Accessory Power (RAP) on page 9‑21. This position locks the ignition and transmission. The key can be removed in LOCK/OFF. Do not turn the engine off when the vehicle is moving. This will cause a loss of power assist in the brake and steering systems and disable the airbags. The ignition switch has four different positions. In order to shift out of P (Park), the ignition must be in ON/RUN or ACC/ACCESSORY and the brake pedal must be applied.