Chevrolet 2001 Impala Owner's Manual page 75

If you need a new key, contact your Chevrolet dealer for
assistance. In an emergency, contact Chevrolet Roadside
Assistance. See "Roadside Assistance" in the Index for
more information.
One key is used for the
ignition, the doors and
all other locks.
NOTICE:
Your vehicle has a number of features that can
help prevent theft. But you can have a lot of
trouble getting into your vehicle if you ever lock
your key inside. You may even have to damage
your vehicle to get in. So be sure you have an
extra key.
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