GM Service Manual Online
For 1990-2009 cars only

Fasten Belts Chime

If the driver's seat belt is unbuckled, the left front seat belt switch closes and grounds CKT 238 (BLK/WHT). CKT 238 (BLK/WHT) applies a ground signal input to the body control module (SBM) at connector C1 terminal C3. When you turn the ignition switch to the START position, or the RUN position, the SBM turns on the fasten seat belt warning chime for 4-8 seconds. The module, at the same time, applies a control signal to CKT 234 (YEL) and lights the FASTEN BELTS indicator for 4-8 seconds. When the chime stops, the indicator illuminates for 20 seconds. After 20  seconds, the indicator flashes. If the driver' s seat belt is buckled during the 4-8 second warning period, the chime stops and the indicator turns off.

Key in Ignition Chime

The key in ignition warning chime sounds with the key in ignition switch, the left front door open, and the key is in the RUN position, or the START position. Inserting a key in the ignition switch closes the ignition switch closes the ignition key warning switch. The switch grounds CKT 80 (LT GRN). CKT 80 (LT GRN) applies a ground input to the remote function actuator (RFA) module at terminal A9. The RFA module in turn applies a signal on CKT 1845 (LT GRN) to the body control module (SBM) at terminal C10. The SBM sounds the key in ignition warning chime.

Lamps On Chime

The lamps on warning chime sounds when the following conditions exist:

    • The left front door is open.
    • The body control module (SBM) does not sense voltage at the lamps on input CKT 549 (PPL/WHT).
    • The ignition switch is not in the RUN position, or the START position.