Chevrolet 2008 Silverado 1500 Pickup Owner's Manual page 117

B (ACC/ACCESSORY): This position lets things like
the radio and the windshield wipers operate while
the engine is off.
Lengthy operation of features such as the radio in the
ACC/ACCESSORY ignition position and the ON/RUN
position may drain the battery and prevent your vehicle
from starting. Do not operate your vehicle in the ACC/
ACCESSORY ignition position for a long period of time.
C (ON/RUN): This is the position for driving. It is the
position the ignition switch returns to after the engine
starts, and the key is released.
The battery could be drained if you leave the key in the
ACC/ACCESSORY or ON/RUN position with the engine
off. 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 position starts the engine.
Key In the Ignition
Never leave your vehicle with the keys inside, as it is an
easy target for joy riders or thieves. If you leave the key in
the ignition and park your vehicle, a chime will sound,
when you open the driver's door. Always remember to
remove your key from the ignition and take it with you.
This will lock your ignition and transmission. Also, always
remember to lock the doors.
The battery could be drained if you leave the key in the
ignition while your vehicle is parked. You may not be
able to start your vehicle after it has been parked for an
extended period of time.
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