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Mercedes-Benz Sprinter / Dodge Sprinter. Manual - part 246

REMOVAL - OUTBOARD

WARNING: To avoid personal injury or death, during
and

following

any

seat

belt

service,

carefully

inspect all seat belts, buckles, mounting hardware,
retractors, and anchors for proper installation, oper-
ation, or damage. Replace any belt that is cut,
frayed, or torn. Straighten any belt that is twisted.
Tighten any loose fasteners. Replace any belt that
has a damaged or inoperative buckle or retractor.
Replace any belt that has a bent or damaged latch
plate or anchor plate. Never attempt to repair a seat
belt component. Always replace damaged or faulty
seat belt components with the correct, new and
unused

replacement

parts

listed

the

DaimlerChrysler Mopar Parts Catalog.

(1) Unsnap and remove the plastic cover from the

screw that secures the outboard rear seat belt buckle
to the right side of the seat cushion frame (Fig.
37).

(2) Remove the screw that secures the outboard

rear seat belt buckle to the rear seat cushion frame.

(3) Remove the outboard rear seat belt buckle from

the right side of the rear seat cushion frame.

INSTALLATION

INSTALLATION - INBOARD

WARNING: To avoid personal injury or death, during
and

following

any

seat

belt

service,

carefully

Tighten any loose fasteners. Replace any belt that
has a damaged or inoperative buckle or retractor.
Replace any belt that has a bent or damaged latch
plate or anchor plate. Never attempt to repair a seat
belt component. Always replace damaged or faulty
seat belt components with the correct, new and
unused

replacement

parts

listed

the

DaimlerChrysler Mopar Parts Catalog.

(1) Position the inboard rear seat belt buckle to

the rear seat cushion frame (Fig. 36).

(2) Install and tighten the screw that secures

either the inboard rear seat belt buckle to the rear
seat cushion frame. Tighten the screw to 35 N·m (26
ft. lbs.).

(3) Reinstall the plastic shield onto the back of the

rear seat. (Refer to 23 - BODY/SEATS/REAR SEAT
BACK SHIELD - INSTALLATION).

(4) Reinstall the rear bench seat into the vehicle.

INSTALLATION - OUTBOARD

WARNING: To avoid personal injury or death, during
and

following

any

seat

belt

service,

carefully

replacement

parts

listed

the

DaimlerChrysler Mopar Parts Catalog.

(1) Position the rear seat belt buckle to the right

outboard side of the rear seat cushion frame (Fig.
37).

(2) Install and tighten the screw that secures the

outboard rear seat belt buckle to the rear seat cush-
ion frame. Tighten the screw to 35 N·m (26 ft. lbs.).

(3) Reinstall the plastic cover onto the screw that

secures the rear seat belt buckle to the right out-
board side of the rear seat cushion frame.

SEAT BELT SWITCH

DESCRIPTION

The seat belt switch is a small, normally closed,

single pole, single throw, leaf contact, momentary
switch. Only one seat belt switch is installed in the
vehicle, and it is integral to the driver side front seat
belt buckle unit. The seat belt switch is connected to
the vehicle electrical system through a two-wire pig-
tail wire harness and connector to a dedicated take

Fig. 37 Outboard Rear Seat Belt Buckle

1 - REAR SEAT BACK TRIM
2 - REAR SEAT BELT BUCKLE
3 - REAR SEAT CUSHION TRIM
4 - SCREW & COVER

RESTRAINTS

8O - 31

out and connector of the vehicle wire harness located
within the driver side front seat riser.

The seat belt switch cannot be adjusted or repaired

and, if faulty or damaged, the entire driver side seat
belt buckle unit must be replaced.

OPERATION

The seat belt switch is designed to control a path

to ground for the seat belt switch sense input of the
Electro-Mechanical Instrument Cluster (EMIC). The
seat belt switch contact is actuated by the seat belt
latch plate being inserted in to the buckle. When the
seat belt latch plate is inserted into the buckle far
enough to be engaged by the seat belt buckle latch,
the switch leaf contact opens the seat belt switch
sense circuit ground path; and, when the seat belt
latch plate is released and extracted from the seat
belt buckle latch the switch leaf contact is released,
closing the circuit to ground.

The seat belt switch is connected is series between

ground and the seat belt switch sense input of the
instrument cluster. The seat belt switch receives
ground at all times through its pigtail wire connec-
tion to the vehicle wire harness from another take
out of the vehicle wire harness. An eyelet terminal
connector on the vehicle wire harness ground take
out is secured under a nut to a ground stud located
on the floor panel within the driver side front seat
riser. The seat belt switch may de diagnosed using
conventional diagnostic tools and methods.

SEAT BELT TENSIONER

DESCRIPTION

Front seating position seat belt tensioners supple-

ment the standard driver and optional passenger air-
bags for all versions of this model. When equipped,
the seat belt tensioner is integral to the front seat
belt and retractor units, which are secured to the
inner B-pillars of the vehicle (Fig. 38). Each retractor
is concealed beneath the molded plastic B-pillar trim.
The seat belt tensioner consists primarily of a tubu-
lar steel housing, a piston, a cable, a torsion bar, and
a small pyrotechnically activated gas generator. All of
these components are located on one side of the
retractor spool on the outside of the retractor housing
except for the torsion bar, which serves as the spin-
dle upon which the retractor spool rotates. The seat
belt tensioner is controlled by the Airbag Control
Module (ACM) and is connected to the vehicle elec-
trical system through a dedicated take out of the
vehicle wire harness by a keyed, snap-fit molded
plastic connector insulator to ensure a secure connec-
tion.

The seat belt tensioner cannot be repaired and, if

faulty or damaged, the entire front seat belt and
retractor unit must be replaced. If the front airbags
have been deployed, the seat belt tensioners have
also been deployed. The seat belt tensioner is not
intended for reuse and must be replaced following a

Fig. 38 Seat Belt Tensioner

1 - TURNING LOOP
2 - LATCH PLATE
3 - LOWER ANCHOR
4 - RETRACTOR
5 - TENSIONER

8O - 32

RESTRAINTS

deployment. A growling or grinding sound while
attempting to operate the seat belt retractor is a sure
indication that the seat belt tensioner has been
deployed and requires replacement. (Refer to 8 -
ELECTRICAL/RESTRAINTS/FRONT SEAT BELT &
RETRACTOR - REMOVAL).

OPERATION

The seat belt tensioners are deployed in conjunc-

tion with the airbags by a signal generated by the
Airbag Control Module (ACM) through the driver and
passenger seat belt tensioner line 1 and line 2 (or
squib) circuits (Fig. 39). When the ACM sends the
proper electrical signal to the tensioners, the electri-
cal energy generates enough heat to initiate a small
pyrotechnic gas generator. The gas generator is
installed so that it directs its expelled gas at the
underside of the piston in the cylinder. The piston is
connected to a cable that is wound around a pulley
on one end of the retractor spool. As the gas expands,
it propels the piston through the tube, which pulls
the cable and rotates the retractor spool to take up
slack in the seat belt webbing.

Once a seat belt tensioning sequence has been

completed, the forward momentum of the occupant

results in deformation of the torsion bar. Removing
excess slack from the front seat belts not only keeps
the occupants properly positioned for an airbag
deployment following a frontal impact of the vehicle,
but also helps to reduce injuries that the occupant
might otherwise experience in a frontal impact event
as a result of harmful contact with the steering
wheel, steering column, instrument panel and/or
windshield. The torsion bar is designed to deform in
order to control the loads being applied to the occu-
pant by the seat belt during a frontal impact, further
reducing the potential for occupant injuries.

The ACM monitors the condition of the seat belt

tensioners through circuit resistance. The ACM will
illuminate the airbag indicator in the ElectroMe-
chanical Instrument Cluster (EMIC) and store a
Diagnostic Trouble Code (DTC) for any fault that is
detected. For proper diagnosis of the seat belt ten-
sioners, a diagnostic scan tool is required. Refer to
the appropriate diagnostic information.

SEAT BELT TURNING LOOP
ADJUSTER

REMOVAL

WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental

restraint

system

before

attempting

any

steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.

WARNING: To avoid personal injury or death, during
and

following

any

seat

belt

service,

carefully

replacement

parts

listed

the

DaimlerChrysler Mopar Parts Catalog.

(1) Move the front seat to its most forward position

for easiest access to the B-pillar trim.

Fig. 39 Seat Belt Tensioner Operation

1 - TUBE
2 - PISTON
3 - CABLE
4 - CYLINDER

RESTRAINTS

8O - 33

(2) Disconnect and isolate the battery negative

cable. Wait two minutes for the system capacitor to
discharge before further service.

(3) Remove the trim panel from the inside of the

B-pillar. (Refer to 23 - BODY/INTERIOR/B-PILLAR
TRIM - REMOVAL).

(4) Pull the height adjuster trim away from the

upper B-pillar to disengage the driver from the lug of
the height adjuster (Fig. 40).

(5) Remove the nut that secures the front seat belt

turning loop to the height adjuster (Fig. 41).

(6) Remove the front seat belt turning loop from

the height adjuster.

(7) Remove the two screws that secure the seat

belt turning loop height adjuster to the upper inner
B-pillar (Fig. 42).

Fig. 40 Turning Loop Height Adjuster

1 - HEIGHT ADJUSTER TRIM
2 - LUG
3 - HEIGHT ADJUSTER
4 - DRIVER

Fig. 41 Front Seat Belt Turning Loop

1 - HEIGHT ADJUSTER
2 - NUT
3 - FRONT SEAT BELT

Fig. 42 Seat Belt Turning Loop Adjuster Remove/

Install

1 - SCREW (2)
2 - ADJUSTER
3 - B-PILLAR

8O - 34

RESTRAINTS

Content .. 244 245 246 247 ..