GM Service Manual Online
For 1990-2009 cars only

The seat belt/ ignition key/ lamps alarm provides an audible warning for the following signals:

    • The fasten seat belt reminder
    • The key in the ignition reminder
    • The headlamps ON reminder

Headlamps ON Reminder

Voltage applies to the seat belt/ ignition key/ lamps alarm connector terminal A1, lighting on input, when the headlamp switch is in the PARK or HEAD position.

The seat belt/ ignition key/ lamps alarm sounds the headlamps ON reminder when the following 2 conditions exist:

    • Voltage is present at the lights ON input, terminal A1.
    • No voltage is present in the ignition switch input, terminal D2.

Key-In-Ignition Reminder

The ignition key warning switch closes when the ignition key is in the ignition lock cylinder. The left front doorlock closes when the driver side door is open. When the ignition key warning switch and the left front doorlock switch are closed, the CKT 80 and CKT 159 are grounded.

The seat belt/ ignition key/ lamps alarm sounds the key in ignition reminder when the following 2 conditions exist:

    • The seat belt/ ignition key/ lamps alarm senses a voltage drop in the key in ignition input, terminal C1
    • No voltage is present in the ignition switch input, terminal D2

Fasten Seat Belt Reminder

The seat belt/ ignition key/ lamps alarm applies voltage to the driver seat belt switch CKT 238 when the ignition switch is in the RUN, BULB TEST, and START positions.

When the driver side seat belt is released, the driver seat belt switch closes, grounding CKT 238. The seat belt/ ignition key/ lamps alarm senses a voltage drop at the seat belt switch input, terminal A2.

When the driver side seat belt is fastened, the driver side seat belt switch will open. The seat belt/ ignition key/ lamps alarm senses the voltage at the seat belt switch input, terminal A2.

The seat belt/ ignition key/ lamps alarm sounds the fasten seat belt reminder chime for 4 to 8 minutes, or until the seat belt is fastened, when the following 2 conditions exist:

    • Voltage is present at the ignition switch input, terminal D2.
    • The seat belt switch is grounded, terminal A2.

The 4 to 8 second chime sound period starts at the beginning of the ignition cycle and does not repeat during that ignition cycle.

The seat belt/ ignition key/ lamps alarm controls the fasten belts indicator.

The seat belt/ ignition key/ lamps alarm applies voltage to CKT 234 and turns ON the fasten belts indicator when the following 2 conditions exist:

    • The driver side seat belt switch is closed (the driver side seat belt is released).
    • Voltage is present in the ignition switch input, terminal D2.

When the driver side seat belt switch is open (the driver side seat belt is fastened), the seat belt/ ignition key/ lamps alarm does not apply any voltage to CKT 234, turning OFF the fasten belts indicator.