Buick REGAL 1997 Manual page 121

Illuminated Entry includes a feature called theater
dimming. With theater dimming, the lamps don't just
turn off at the end of the delay time. Instead, they slowly
dim after the delay time until they go out. The delay
time is canceled if you turn the- ignition key to RUN or
START, so the lamps will dim right away.
When the ignition is on, Illuminated Entry is inactive,
which means the courtesy lamps won't come on unless
a door is opened.
Delayed Entry Lighting
Delayed Entry Lighting illuminates your vehicle's interior
for a period of time after a l l the doors have been closed.
The ignition must be off for Delayed Entry Lighting
to work. Just after all the doors have been closed,
the Delayed Entry Lighting feature will continue to
work until:
The ignition is turned to the RUN position.
0
The doors are locked.
0
An illumination period of 25 seconds has elapsed.
If during the illumination period a door is opened, the
timed illumination period will be canceled and the
interior lamps will remain on since a door is open.
Delayed Exit Lighting
This feature illuminates your vehicle's interior for a
period of time after the ignition key is removed from
the ignition.
The vehicle's ignition must be off for Delayed Exit
Lighting to work. When the ignition key is removed,
interior illumination will activate and remain on until:
The ignition is turned to the RUN position.
The power door locks are activated.
0
An illumination period of 25 seconds has elapsed.
If during the illumination period a door is opened, the
timed illumination period will be canceled and the
interior lamps will remain on since a door is open.