GM Service Manual Online
For 1990-2009 cars only

The interior lamps system consists of the following two functions:

    • An illuminated entry that activates the interior lamps when dark ambient lighting is detected by the headlamp automatic control ambient light sensor.
    • An interior lamps delay that deactivates the interior lamps after 10 minutes.

The body control module (BCM) activates both of the above functions through the multifunction relay module K134 under the following conditions:

    • Manually locking a side door lock.
    • Manually unlocking a side door lock.
    • Opening a front side door and then closing the front side door.
    • The use of the remote keyless entry (RKE) to unlock the side doors.

The multifunction relay K134 supplies B+ to the interior lamps (except the reading lamps) when the BCM energizes the delayed interior lamp relay. The interior lamp relay provides a ground path for the following:

    • The dome lamp.
    • The front side door courtesy lamps.
    • The roof rail courtesy lamps.

The above lamps also activate whenever the headlamp switch is in the PARK position and when the interior lamps switch is pressed.

The IP compartment lamp illuminates when the IP compartment is opened, and when the delay interior lamp relay is energized.

The rear compartment courtesy lamp illuminates when the rear compartment lid is opened. This also activates the rear compartment lid release open indicator lamp in the instrument cluster.

The rear side door courtesy lamps illuminate when the rear side door opens. The reading lamps can be manually activated when the ignition switch is in the ON position.