Seat Belt Control Module: Description and Operation

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

Conditions to Move Carrier from the A-Pillar to the 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 battery voltage), the passive restraint control 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 control module will apply power to the driver motor. This will send the carrier from the A-pillar to the B-pillar (pins 2 & 17 battery voltage, 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 the B-Pillar to the 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 fuel shutoff switch is set (pin 12 floating), the passive restraint control 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 control 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 fuel shutoff switch is tripped (pin 12 grounded), no action will occur.

Conditions to Activate the Seat Belt Lamp
When the passive restraint control 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 warning lamp.

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 battery voltage) and either of the shoulder belts are retracted in (pin 14 or 15 floating/not grounded).

NOTE: The warning chime module works with the warning lamp.

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

When the ignition key is in the ON position (pin 25 battery voltage), and either shoulder belt is retracted 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 retracting in the other shoulder belt (floating/grounding pin 14 or 15).