GM Service Manual Online
For 1990-2009 cars only

Seat Belt Warning Alarm

The seat belt alarm is located in the body control module (BCM). The BCM is located under the center instrument panel sound insulator. Refer to Body Control Module Replacement in Body Control System. For more information, refer to Symptoms - Audible Warnings .

Multifunction Alarm Warning System

Some models use an audio alarm system in order to remind the driver to perform the following actions:

    • Fasten the seat belts
    • Remove the ignition key
    • Turn OFF the headlamps

This system uses an alarm that sounds 3-5 times. The alarm activates a warning lamp on the instrument cluster when the ignition switch is turned to the RUN position and the driver's seat belt is not buckled. If the ignition switch is turned OFF and the headlamps are ON, then the BCM sounds (chimes) in order to remind the driver to turn OFF the headlamps. The alarm also sounds if the driver's door opens while the key is left in the ignition switch. If the instrument panel lamp dimmer thumbwheel is turned OFF and the headlamps are ON, the alarm does not sound if the ignition switch is turned OFF. The alarm module mounts to the convenience center.

The power distribution center is located at the right side of the steering column. The power distribution center is part of the instrument panel harness assembly. The following components mount to the power distribution center:

    • The hazard flasher
    • The turn signal flasher
    • The alarm module

The relay center, also called the underhood fuse block, is located under the hood. The following components mount to the relay center:

    • The DRL relay
    • The horn relay
    • The foglamp relay
    • The fuel pump relay

The seat belt warning system switch is located in the seat belt buckle. The seat belt warning system switch provides ground when the buckle is not joined with the other part of the belt. When the belt is not buckled while the ignition is in the RUN position, the retractor switch closes and the alarm is activated.

The headlamp-on warning circuit activates when the headlamps are ON and the ignition is in one of the following positions:

    • OFF
    • LOCK
    • ACC

The BCM senses voltage from the instrument panel dimmer switch and activates an audible warning. For more information, refer to Symptoms - Audible Warnings .