GM Service Manual Online
For 1990-2009 cars only

Important: Terminals of the lamps that are not label may be indexed in any order.

Courtesy Lights

The courtesy lights come on under the following conditions:

    • Any door is opened.
    • The interior lamp switch is in the ON position.
    • The keyless entry transmitter unlocks the doors (illuminated entry).

When the key is removed from the ignition switch with all of the doors closed, the courtesy lights light for approximately 25 seconds before fading out.

Battery positive voltage (B+) is applied at all times through the IP fuse block CTSY LP/PWR MIR fuse 6A via CKT 640 (ORN) through the body control module (MALL) to the courtesy lights via CKT 1732 (ORN). The MALL provides a ground through CKT 156 (WHT) for the courtesy lights under the following conditions:

    • The MALL receives an input from a door being opened.
    • The MALL receives an input from the interior lamp being turned ON.
    • The MALL receives an input from the doors being unlocked using the keyless entry transmitter.

The courtesy lamps then light.

When the courtesy lights are activated by opening and closing a door, the courtesy lights will remain on for approximately 25 seconds before fading out after all of the doors are closed. If the ignition switch is turned to START or RUN within the 25 seconds, the lights immediately begin to fade out. If a door is left open, the MALL removes battery positive voltage (B+) to the courtesy lights after 10 minutes. When the courtesy lights are activated by the interior lamp switch, the lights remain on as long as the interior lamp switch is in the ON position. When the courtesy lights are activated by unlocking the doors using the keyless entry transmitter, the lights remain on for approximately 40 seconds. If the doors are locked using the keyless entry transmitter within the 40 seconds, the lights immediately begin to fade out.

Body Control Module (MALL) Diagnostic Mode

For a detailed explanation of the MALL module diagnostic mode, refer to Body Control Module Cell 51.

IP Compartment Lamp

The IP compartment lamp switch is permanently grounded. The MALL provides battery positive voltage (B+) to the lamp during inadvertent power. When the IP compartment is opened, the IP compartment lamp then lights.

Rear Compartment Lamp

The MALL provides battery positive voltage (B+) to the lamp during inadvertent power. When the rear compartment is opened, the rear compartment lid latch switch closes, providing a ground path to the lamp. The rear compartment lamp then lights.

Underhood Lamp (Buick)

With the headlamp switch in PARK, battery positive voltage (B+) is applied through the IP fuse block INTERIOR LPS fuse 8B to the underhood lamp. When the engine compartment lid is opened, the switch closes, providing a ground path to the lamp. The underhood lamp then lights.

Vanity Mirror Lamps

The MALL provides voltage to the lamp during inadvertent power. The vanity mirror cover switch is permanently grounded to G202. When the vanity mirror cover is opened, the cover switch is closed, providing a ground path to the lamp. The vanity mirror lamp then lights. You may adjust the intensity of the vanity mirror lamp by sliding the dimmer switch on each vanity mirror.

Theater Dimming

At the end of an interior illumination function, the interior lamps gradually dim from full intensity to off in 3 seconds.

Inadvertent Power

The inadvertent power function prevents battery run down by deactivating all of the courtesy lamps. The MALL removes power from the interior lamps after 10 minutes under the following conditions:

    • Ignition switch in the OFF position
    • Any key in or out input
    • Any courtesy lamp activated
    • No other interior lamps on input is received