GM Service Manual Online
For 1990-2009 cars only

Safety Belt Warning Buzzer

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

    • The GAUGES fuse 4
    • CKT 39 (PNK)

When you first turn the ignition switch to the START position or the RUN position, voltage from the BCM is supplied to the fasten seat belt indicator through CKT 237 (YEL). The indicator remains lit for about 5 seconds.

If the driver safety belt is not buckled, a ground is not applied to the BCM from CKT 238 (BLK/WHT) from the seat belt switch. The chime will sound for about 5 seconds.

Key-In Warning Buzzer

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

    • The Underhood Fuse Block TBC fuse
    • CKT 1140 (ORN)

The chime sounds if all of the following conditions exist:

    • The key is in the ignition switch.
    • The vehicle is not running.
    • The left door is open.

When the door is open, the left front door jamb switch closes to ground. This action provides a ground to the BCM through the following components:

    • CKT 126 (TAN)
    • The LH Door Jamb Switch
    • CKT 1050 (BLK)
    • SP203
    • C203 cavity F12
    • G203

The chime or the buzzer 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 at all times to the BCM through the following components:

    • The Underhood Fuse Block TBC fuse
    • CKT 1140 (ORN)

The chime sounds if all of the following conditions exist:

    • The headlamp switch is in the PARK or Head position
    • The ignition switch is not in the RUN or START position
    • The headlamp dimmer switch is not at the maximum dimming position

With the headlamp 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 the RUN position or the START position, voltage is supplied through GAUGES Fuse 4 to the alarm module through CKT 39 (PNK). The 2 voltages are sensed. The alarm is not sounded. Once the voltage is not sensed by the BCM and the headlamp switch is still in the PARK or HEAD position the BCM enables the chime until the headlamps are turned off.