FORD 2002 F-150 v.1 - Manual (Page 136)

The safety belt pretensioners are designed to activate only during certain
frontal or near-frontal collisions with sufficient longitudinal deceleration.
A safety belt pretensioner is a device which tightens the webbing of the
lap and shoulder belts in such a way that they fit more snugly against
the body.
The driver and front outboard passenger safety belt system (including
retractors, buckles and height adjusters) must be replaced if the vehicle
is involved in a collision that results in the activation of the safety belt
pretensioners. Refer to the Safety belt maintenance section in this
chapter.
Failure to replace the safety belt assembly under the above
conditions could result in severe personal injuries in the event of
a collision.
Front safety belt height adjustment (if equipped)
If your vehicle has seat integrated restraints you will not have a safety
belt height adjuster.
Regular Cab and SuperCab vehicles have safety belt height adjustments
for the driver and front passenger. SuperCrew vehicles have these
adjustments for the driver, front passenger and rear outboard
passengers. Adjust the height of the shoulder belt so the belt rests
across the middle of your shoulder.
Seating and Safety Restraints
136