2013 Chevrolet Express 1500 Cargo Owner Manual - Page 206

9-16 Driving and Operating { WARNING Turning off the vehicle while moving may cause loss of power assist in the brake and steering systems and disable the airbags. While driving, only shut the vehicle off in an emergency. If the vehicle cannot be pulled over, and must be shut off while driving, turn the ignition to ACC/ ACCESSORY. 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. 2 (ACC/ACCESSORY): This is the position in which you can operate things like the radio and the windshield wipers when the engine is off. 3 (ON/RUN): This position can be used to operate the electrical accessories and to display some instrument cluster warning and indicator lights. This position can also be used for service and diagnostics, and to verify the proper 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. 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. 4 (START): This is the position that starts the engine. When the engine starts, release the key. The ignition switch returns to ON/RUN for driving. A warning tone will sound when the driver door is opened, the ignition is in ACC/ACCESSORY or LOCK/OFF and the key is in the ignition. Starting the Engine If the vehicle has a diesel engine, see the Duramax diesel supplement. To place the transmission in the proper gear: 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.