GM Service Manual Online
For 1990-2009 cars only

For vehicles with courtesy lamps, they come on and stay on for a set time whenever the unlock symbol is pressed on the Remote Keyless Entry (RKE) transmitter, if the vehicle has one.

If a door is opened, the lamps stay on while it is open and then turn off automatically about 20 seconds after the door is closed. If the unlock symbol is pressed and no door is opened, the lamps turn off after about 20 seconds.

Entry lighting includes a feature called theater dimming. With theater dimming, the lamps do not turn off at the end of the delay time. Instead, they slowly dim and then go out. The delay time is canceled if the ignition key is turned to ON/RUN or the power door lock switch is pressed. The lamps will dim right away.

When the ignition is on, illuminated entry is inactive, which means the courtesy lamps will not come on unless a door is opened.