2012 GMC Acadia Owner's Manual - Page 270

9-16 Driving and Operating operation of the malfunction indicator lamp as may be required for emission inspection purposes. The switch stays in this position when the engine is running. The transmission is also unlocked in this position. If you leave the key in the ACC/ACCESSORY or ON/RUN position with the engine off, the battery could be drained. You may not be able to start the vehicle if the battery is allowed to drain for an extended period of time. Notice: Do not try to shift to P (Park) if the vehicle is moving. If you do, you could damage the transmission. Shift to P (Park) only when the vehicle is stopped. Starting Procedure 1. With your foot off the accelerator pedal, turn the ignition to START. When the engine starts, let go of the key. The idle speed will slow down as the engine warms. Do not race the engine immediately after starting it. Operate the engine and transmission gently to allow the oil to warm up and lubricate all moving parts. The vehicle has a Computer-Controlled Cranking System. This feature assists in starting the engine and protects components. If the ignition key is turned to the START position, and then released when the engine begins cranking, the engine will continue cranking for a few seconds or until the If the vehicle cannot be pulled over, and must be shut off while driving, turn the ignition to ACC/ ACCESSORY. The steering can bind with the wheels turned off center. If this happens, move the steering wheel from right to left while turning the key to ACC/ACCESSORY. If this does not work, then the vehicle needs service. ACC (ACC/ACCESSORY): This is the position in which you can operate the electrical accessories or items plugged into the accessory power outlets. This position unlocks the ignition and steering wheel. Use this position if the vehicle must be pushed or towed. This position can be used to operate the electrical accessories and to display some instrument panel warning and indicator lights. This position can also be used for service and diagnostics, and to verify the proper / (START): This is the position that starts the engine. When the engine starts, release the key. The ignition switch will return to ON/RUN for driving. R (ON/RUN): Starting the Engine Move the shift lever to P (Park) or N (Neutral). The engine will not start in any other position. To restart the engine when the vehicle is already moving, use N (Neutral) only.