Seat Belt Control Module: Description and Operation

This description applies to the operation of the passive restraint system. The chart indicates the system inputs and pins necessary for application to the driver's and passenger's side of the system.

Conditions To Move Carrier From A-Pillar To B-Pillar
To move the carrier from the A-pillar to the B-pillar when the door is closed (pin 13 floating/not grounded), and the ignition key is in the ON position (pin 25 high), the passive restraint module will check the B-pillar limit switch (pin 18).

If the B-pillar limit switch is not activated (pin 18 floating/not-grounded), the passive restraint module will apply power to the driver motor. This will send the carrier from the A-pillar to the B-pillar (pins 2 & 17 high, pins 3 & 4 grounded), until the B-pillar limit switch is activated (pin 18 grounded).

If the B-pillar limit switch is activated (pin 18 grounded), no action will occur.

Conditions To Move The Carrier From B-Pillar To A-Pillar
To move the carrier from the B-pillar to the A-pillar when the door is opened (pin 13 grounded), and the inertia switch is set (pin 12 floating), the passive restraint module will check the A-pillar limit switch (pin 5).

If the A-pillar limit switch is not activated (pin 5 floating), the passive restraint module will apply power to the driver motor. This will send the carrier from the B-pillar to the A-pillar (pins 3 & 4 high, pins 2 & 17 grounded), until the A-pillar limit switch is activated (pin 5 grounded).

If the A-pillar limit switch is activated (pin 5 grounded), or the inertia switch is tripped (pin 12 grounded), no action will occur.

Conditions To Activate The Seat Belt Light
When the passive restraint module determines a seat belt warning is required, the fasten seat belt indicator output (pin 16), supplies a ground to the Fasten Belt Indicator (FBI). This action activates the seat belt light.

When the ignition key is in the ON position (pin 25 high), and both of the B-pillar limit switches are not activated (pin 18 or 21 floating/not-grounded), the FBI output is activated (pin 16 grounded).

The FBI is also activated when the ignition key is in the ON position (pin 25 high), and either of the shoulder belts are spooled in (pin 14 or 15 floating/not-grounded).

NOTE: The Warning Chime Module interfaces with the warning light.

Conditions To Activate The Warning Chime
When the passive restraint module determines that a warning is required, the audible chime output (pin 1) supplies a ground to the warning chime module.

When the ignition key is in the ON position (pin 25 high), and either shoulder belt is spooled in (pin 14 or 15 floating/not-grounded), the chime output is activated (pin 1 grounded) for five seconds. If this output has been triggered and timed out, it can be triggered again by spooling in the other shoulder belt (floating/grounding pin 14 or 15).