2012 Chevrolet Colorado Owner's Manual - Page 210

9-28 Driving and Operating 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 your vehicle if the battery is allowed to drain for an extended period of time. D (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. B (ACC/ACCESSORY): This is the position in which you can operate the electrical accessories or items plugged into the accessory power outlets. On automatic transmission vehicles, this position unlocks the ignition. On manual transmission vehicles, it unlocks the ignition and steering wheel . Use this position if the vehicle must be pushed or towed. C (ON/RUN): This position can be used to operate the electrical accessories and to display some instrument panel 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. The transmission is also unlocked in this position on automatic transmission vehicles. Starting the Engine Place the transmission in the proper gear. Automatic Transmission Move the shift lever to P (Park) or N (Neutral). The engine will not start in any other position. To restart the vehicle when it is already moving, use N (Neutral) only. 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. Manual Transmission The shift lever should be in N (Neutral) and the parking brake engaged. Hold the clutch pedal down to the floor and start the engine. The vehicle will not start if the clutch pedal is not all the way down.