Diagnostics and testing of seat belts (Focus 1)

Inspection and verification

1. Check the validity of the customer's complaint by using the system.

2. Perform a visual inspection for obvious signs of mechanical and electrical damage.

Visual inspection table

Mechanical factors	Electrical factors
- Loose tape – Damaged/worn tape – Seat belt retractor and tongue assembly – Retraction mechanism – Pyrotechnic tensioner lock	- Indicator lamp light - Chain – Central timer module

3. If an obvious cause for the reported or received complaint is found, correct the fault (if possible) before proceeding to the next step.

4. If the cause of the malfunction is not obvious, clarify the malfunction symptom and refer to the Malfunction Symptom Table.

Table of signs of malfunctions

State	Possible Causes	Action
•Normal mode - The vehicle's occupant safety system is not working	•Broken tooth of the retraction mechanism sensor gear. •Loose tape.	•REFER to Functional Check in this section.

Functional check

WARNING: In the event of an accident involving deployment of the air bags, all seat belts in use at the time of the accident must be removed; new seat belts must be installed. Failure to follow these instructions may result in injury and component damage.

Poor retraction

If the seat belt does not retract correctly, check that the anchor covers and trim are installed correctly and that they do not rub against the seat belt webbing. If necessary, check that the seat belt webbing does not rub against the retractor cover opening at one edge and, if this occurs, correct the condition by loosening the anchor bolt and aligning the retractor so that the seat belt webbing is centered. Then retighten the bolt.



Focus vehicles are equipped with two front and three rear inertia-reel seat belts. These seat belts are "dual sensitivity." This means that the belts have:

• a vehicle motion sensor that locks the seat belt when braking, turning, on sharp ascents and descents, and on sharp bends in the road surface.
• belt movement sensor, which is blocked when the seat belt is pulled out quickly.

Both systems must be fully functional and can be checked using the following tests:

Checking the car motion sensor

Either of the following two procedures can be used to check the vehicle's motion sensor for proper operation. Both methods require two mechanics, but note that larger-than-normal mechanics should not be assigned to perform these tests. This is to ensure that the complete unwinding of the seat belt webbing is not mistaken for proper locking by the seat belt retractor mechanism.

1st method of checking (braking)

WARNING: It is important that during this check, occupants wearing seat belts allow the seat belts to provide restraint and do not anticipate a sudden loss of speed. The steering wheel should not be used as a support. However, both the driver and passenger should be prepared for the possibility that the seat belt will not lock. The passenger should extend their arms in front of them, toward the instrument panel or the back of the front seat (depending on which seat belt is being checked). Failure to follow these guidelines could result in injury.

• Choose a quiet stretch of road or a private road for this test. Make sure the road is clear and you have a full view at all times.
• The driver and passenger should assume normal, comfortable sitting positions. Both people in the car should fasten their seat belts, and the seat belt webbing should be adjusted correctly, without sagging.
• Drive at 10 km/h (6 mph). Do not exceed 10 km/h (6 mph) during this test.
• Press the brake pedal sharply to stop the vehicle. If the vehicle's motion-sensitive locking mechanism is functioning properly, the seat belt webbing will lock and hold the occupant of the seat belt.
• Perform the check twice for each front and rear passenger seat.
• Any seat belt retractor that does not restrain the occupant of the seat belt during this test must not be used. A new seat belt must be installed.

2nd method of checking (turning circle)

This test requires a level, open section of road large enough to allow the vehicle to be driven continuously in a circle with the steering wheel fully engaged.

• The driver must fasten the provided seat belt, and the seat belt webbing must be adjusted correctly, without sagging.
• The passenger must occupy the rear seat with the seat belt properly adjusted.
• Start the engine and, with the steering wheel turned to the full right lock position, drive in a continuous circle at 16 km/h (10 mph). Do not exceed the speed limit of 16 km/h (10 mph) while performing this test.
• At a steady speed, the occupant should attempt to slowly pull the seat belt webbing out of each seat belt retractor in turn. If the vehicle's motion-sensitive locking mechanism is functioning properly, the webbing cannot be pulled out.
• Any seat belt retractor mechanism that allows the webbing to be pulled out during this test must not be used. A new seat belt must be installed.

Checking the elements

With the vehicle stationary on a level, horizontal surface, grasp the seat belt webbing firmly (on the tongue side of the upper seat belt anchor) and quickly pull the webbing outward. The retractor mechanism should lock within 0.25 meters (10 inches), preventing further retraction. Any seat belt retractor mechanism that allows further retraction should not be used. A new seat belt must be installed.