Seat Belt Systems: Description and Operation
WARNING: All safety belt assemblies, including retractors and attaching hardware, should be inspected after any collision. Ford recommends that all safety belt assemblies in use during a collision be replaced unless the collision was minor and a qualified technician finds that the belts show no damage and continue to operate properly. When a motorized passive restraint system in use during a collision is replaced, the opposite motorized shoulder belt and retractor assembly must also be replaced. Safety belt assemblies not in use during a collision should also be inspected and replaced if either damage or improper operation is noted.
Occupant Restraining Devices
The occupant restraining devices include the outboard rear 3-point lap/shoulder belts, the center rear passenger lap belt, the manual front lap belts, and the passive restraint system that controls the front shoulder belts.
Passive Restraint System
The passive restraint system has a control module mounted under the driver's seat, which controls the movement of the front shoulder belts. The front shoulder belts are anchored in a centrally located retractor assembly and are latched to carriers mounted on the track and motor assembly. Front and rear limit switches are mounted on the track and motor assemblies. (These switches are inputs to the control module and provide information regarding the position of the carrier on the track.)
When a door is closed and the ignition switch is in the ON position, the door catch switch sends a signal to the passive restraint control module to operate the motor. The carrier then slides up the track until it reaches the rear limit switch, which cuts the current to stop the operation of the motor.
When a door is opened, the door catch switch sends a signal to the passive restraint control module to operate the motor regardless of what position the ignition switch is in. The carrier then slides down the track until it reaches the front limit switch, which cuts the current to stop operation of the motor.
If a malfunction of the passive restraint system occurs, the system can be operated manually by using a lever to crank the motor. Refer to the Owner Guide for procedures to manually operate the passive restraint system.
Seat Belts
The front lap belts, rear lap/shoulder belts, and center passenger lap belt are conventionally mounted and are not controlled by the passive restraint system.
NOTE: Canadian Escort wagons and 5-door hatchbacks have manual front lap/shoulder belts with fixed tongues. Canadian Escort 3-door hatchbacks have manual front lap/shoulder belts with sliding tongues (except for the Escort GT).
Electrical System
The passive restraint system consists of a passive restraint control module, left and right track and motor assemblies, left and right door catch switches, left and right front limit switches, and left and right rear limit switches. The control module is located under the driver's seat. The track and motor assemblies are located at the B-pillars on all vehicles. The front and rear limit switches are attached to the track assembly. The rear limit switch is not serviceable. The door catch switches are located at the base of the B-pillar. To check the operation of the system, perform the Functional test. A technical description of system operation is also provided.
The shoulder belt will automatically adjust to allow for occupant comfort and freedom of movement. The belt will lock up only during hard breaking or cornering, or during impacts of 8 km/h (5 mph) or more.
The passive restraint system is serviced in two parts:
1. A-pillar limit switch.
2. Track/motor assembly.
Control Module
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).