GM Service Manual Online
For 1990-2009 cars only

Safety Belt Warning Chime

Voltage is supplied to the body control module (BCM) through the following components when the ignition switch is in the START or RUN position:

    • The GAUGES fuse 4
    • CKT 39 (PNK)

When you first turn the ignition switch to START or RUN, a class 2 signal from the BCM is sent to the instrument cluster logic turning ON the fasten seat belt indicator. The indicator comes ON steady for 20 seconds and then flashes for another 55 seconds or goes out when the driver saftey belt is buckled.

When the driver safety belt it buckled, a ground is applied to the BCM through CKT 238 (BLK/WHT) from the seat belt switch causing the lamp and chime to go out. The chime will only sound for about the first 5 seconds of the ignition on cycle.

Key-In Warning Chime

Voltage is supplied at all times to the BCM through the following components:

    • The underhood fuse block fuse 4
    • CKT 1140 (ORN)

The chime sounds if the following conditions exist:

    • The key is in the ignition switch
    • The ignition switch is in one of the following positions:
       - ACC
       - LOCK
       - OFF
    • The right door is open.

When the door is open, the RH door jamb switch on the side of the IP closes. This provides a ground to the BCM through the following components:

    • CKT 126 (TAN)
    • The ignition key alarm switch
    • CKT 80 (LT GRN)

The chime will sound for as long as the door is open and the key is in the ignition switch.

Lamps-On Warning Buzzer

Voltage is supplied through the ILLUM Fuse 12 to the BCM through CKT 44 (DK GRN) when the following conditions exist:

    • The light switch is in HEAD or PARK.
    • The panel dimmer switch is not at the dimmest setting.

With the panel dimmer switch at the dimmest setting, the current to the BCM may be too weak to be sensed by the module. When the ignition switch is turned to RUN or START, voltage is supplied through GAUGES Fuse 4 through CKT 39 (PNK). When the ILLUM and GAUGES fuse voltages are sensed together, the alarm is not sounded.

GAUGES Fuse 4 loses voltage when the ignition switch is in one of the following positions:

    • LOCK
    • OFF
    • ACC