Pontiac 2002 Firebird Owner's Manual page 93

Ensure the shift lever is fully in PARK (P) before
starting the engine. Your vehicle has an automatic
transmission shift lock control system. You have to
fully apply your regular brakes before you can shift
from PARK (P) when the ignition key is in RUN.
If you cannot shift out of PARK (P), ease pressure on
--
the shift lever push the shift lever all the way into
PARK (P) and also release the shift lever button on floor
shift console models as you maintain brake application.
Then move the shift lever into the gear you wish.
(Press the shift lever button before moving the shift
lever on floor shift console models.) See "Shifting Out
of PARK (P)" in the Index.
REVERSE (R): Use this gear to back up.
NOTICE:
Shifting to REVERSE (R) while your vehicle is
moving forward could damage your transmission.
Shift to REVERSE (R) only after your vehicle
is stopped.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission, see
"Stuck: In Sand, Mud, Ice or Snow" in the Index.
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