Cadillac 2010 DTS - Manual (Page 131)

Ignition Positions
The ignition switch has four different positions:
In order to shift out of P (Park), ignition must be in the
ON/RUN or ACC/ACCESSORY and the brake pedal
must be applied.
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.
A (LOCK/OFF): This is the only position in which the
ignition key can be inserted or removed. This position
locks the ignition and transmission and steering column.
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 doesn’t work, the vehicle needs service.
B (ACC/ACCESSORY): This position lets the radio and
windshield wipers operate while the engine is off. To
use ACC/ACCESSORY, turn the key clockwise.
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