2010 Buick LaCrosse Owner's Manual - Page 239

Driving and Operating ON/RUN/START: This position is for driving and starting. With the ignition off, and the brake pedal applied, pressing the button once will place the ignition system in ON/ RUN/START. Once engine cranking begins, release the button. Engine cranking will continue until the engine starts. See Starting the Engine on page 8‑20 for more information. The ignition will then remain in ON/RUN. To place the ignition in ON/RUN/ START from OFF without starting the engine, press the button two times without your foot on the brake pedal. The battery could be drained if you leave the ignition in the ON/RUN/ START position with the engine off. You may not be able to start the vehicle if the battery is allowed to drain for an extended period of time. 8-19 Ignition Positions (Key Access) To shift out of P (Park), turn the ignition to ON/RUN and apply the brake pedal. A (LOCK/OFF): This is the only position from which the key can be removed. This locks the ignition and automatic transmission. The shift lever must be in P (Park) to turn the ignition switch to the LOCK/OFF position. The ignition switch can bind in the LOCK/OFF position 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. B (ACC/ACCESSORY) : This position provides power to some of the electrical accessories. It unlocks the ignition. The transmission is also unlocked in this position on automatic transmission vehicles. To move the key from ACC/ ACCESSORY to LOCK/OFF, the shift lever must be in P (Park). The ignition switch has four different positions. 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/retailer.