Chevrolet 2001 Impala Owner's Manual page 163

Door Ajar
United States
This message will appear if the driver's door or one of
the passenger's doors is not completely closed and the
ignition is in ON.
If you are in a forward or reverse gear position you will
also hear four chimes.
Security
Canada
This message is displayed to monitor the
Passlock
If the security message is displayed continuously while
driving and stays on, there may be a problem with the
Passlock system. Your vehicle will not be protected by
Passlock, and you should see your dealer for service.
United States
R
system.
Canada
2-93