2006 MERCEDES-BENZ SPRINTER airbag

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 RESTRAINTSVA

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 occupantresults 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
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 in 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
VARESTRAINTS 8O - 33

(8) Remove the seat belt turning loop height
adjuster from the inner B-pillar.
INSTALLATION
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
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 in the
DaimlerChrysler Mopar Parts Catalog.
(1) Position the seat belt turning loop height
adjuster onto the inner B-pillar (Fig. 42).
(2) Install and tighten the two screws that secure
the seat belt turning loop height adjuster to the
upper inner B-pillar. Tighten the screws to 35 N´m
(26 ft. lbs.).
(3) Position the front seat belt turning loop onto
the height adjuster on the upper B-pillar (Fig. 41).
(4) Install and tighten the nut that secures the
front seat belt turning loop to the height adjuster.
Tighten the nut to 35 N´m (26 ft. lbs.).
(5) Position the height adjuster trim to the upper
B-pillar so that the driver on the back of the trim
engages the lug of the height adjuster (Fig. 40).
(6) Reinstall the trim panel onto the inside of the
B-pillar. (Refer to 23 - BODY/INTERIOR/B-PILLAR
TRIM - INSTALLATION).
(7) Reconnect the battery negative cable.
SIDE CURTAIN AIRBAG
DESCRIPTION
Optional side curtain airbags are available for this
model when it is also equipped with dual front air-
bags. These airbags are passive, inflatable, Supple-
mental Restraint System (SRS) components (Fig. 43).
This system is designed to reduce injuries to the
vehicle occupants in the event of a side impact colli-
sion.
Vehicles equipped with side curtain airbags have
two individually controlled curtain airbag units.
These airbag units are concealed and mounted above
the front door openings where they are each secured
to one of the roof side rails. Each folded airbag cush-
ion is contained within a channel in the molded plas-
tic garnish molding that extends along the roof rail
from the A-pillar at the front of the vehicle to just
behind the B-pillar. A tether extends down the A-pil-
lar from the front of the airbag cushion, where it is
secured to the base of the pillar near the belt line
with a screw.
The hybrid-type inflator for each airbag is con-
nected to the airbag cushion by a tubular manifold.
The inflator bracket and the airbag cushion channel
are located with a stamped metal lug to a bore in the
roof rail, then secured with screws at the A-pillar in
the front and the B-pillar in the rear. A two-wire pig-
tail wire is routed from the airbag inflator down the
B-pillar where it connects the unit to a take out of
the vehicle body wire harness with a keyed and
latched connector insulator.
The side curtain airbag unit cannot be adjusted or
repaired and must be replaced if deployed, faulty, or
Fig. 43 Side Curtain Airbag
1 - GRAB HANDLE
2 - B-PILLAR TRIM
3 - SIDE CURTAIN AIRBAG
VARESTRAINTS 8O - 35

in any way damaged. Once a side curtain airbag has
been deployed, the complete airbag unit and all other
visibly damaged components must be replaced.
OPERATION
Each side curtain airbag is deployed individually
by an electrical signal generated by the Airbag Con-
trol Module (ACM) to which it is connected through
left or right curtain airbag line 1 and line 2 (or
squib) circuits. The hybrid-type inflator assembly for
each airbag contains a small canister of highly com-
pressed inert gas. When the ACM sends the proper
electrical signal to the airbag inflator, the electrical
energy creates enough heat to ignite chemical pellets
within the inflator. Once ignited, these chemicals
burn rapidly and produce the pressure necessary to
rupture a containment disk in the inert gas canister.
The inflator and inert gas canister are sealed and
connected to a tubular manifold so that all of the
released gas is directed into the folded side curtain
airbag cushion, causing the cushion to inflate.
As the airbag cushion inflates it will split the gar-
nish molding at a predetermined breakout line and
drop down from the roof rail along the side glass and
body pillars to form a curtain-like cushion to protect
the vehicle occupants during a side impact collision.
The front tether keeps the front portion of the side
curtain bag taut, thus ensuring that the bag will
deploy in the proper position. Following the airbag
deployment, the airbag cushion quickly deflates by
venting the inert gas through the loose weave of the
cushion fabric, and the deflated cushion hangs down
loosely from the roof rail.
REMOVAL
The following procedure is for replacement of a
faulty or damaged side curtain airbag. If the airbag
is faulty or damaged, but not deployed, review the
recommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the side curtain airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deployment
before removing the airbag from the vehicle. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - SERVICE AFTER A SUPPLEMENTAL
RESTRAINT DEPLOYMENT).
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, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to dischargebefore performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: To avoid personal injury or death, when
removing a deployed airbag, rubber gloves, eye
protection, and a long-sleeved shirt should be
worn. There may be deposits on the airbag unit and
other interior surfaces. In large doses, these depos-
its may cause irritation to the skin and eyes.
WARNING: To avoid personal injury or death, use
extreme care to prevent any foreign material from
entering the side curtain airbag, or becoming
entrapped between the side curtain airbag cushion
and the roof rail garnish molding. Failure to
observe this warning could result in occupant inju-
ries upon airbag deployment.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the pinch welt from the front door
opening of the vehicle as needed to access the side
curtain airbag (Fig. 44).
(3) Remove the trim from the inside of the B-pillar.
(Refer to 23 - BODY/INTERIOR/B-PILLAR TRIM -
REMOVAL).
(4) Remove the grab handle from the headliner.
(Refer to 23 - BODY/INTERIOR/ASSIST HANDLE -
REMOVAL).
Fig. 44 Pinch Welt
1 - GRAB HANDLE
2 - B-PILLAR TRIM
3 - PINCH WELT
8O - 36 RESTRAINTSVA

(5) Carefully remove the trim from the A-pillar
that conceals the side curtain airbag front tether
(Fig. 45).
(6) Disconnect the pigtail wire connector for the
side curtain airbag from the vehicle wire harness
connector on the B-pillar (Fig. 46).
(7) Cut the tie wrap that secures the side curtain
airbag pigtail wire to the inside of the B-pillar.
(8) Remove the screw that secures the side curtain
airbag tether retainer to the base of the A-pillar near
the belt line (Fig. 47).(9) Remove the screw that secures the front of the
side curtain airbag to the A-pillar (Fig. 48).
(10) Remove the screw that secures the rear of the
side curtain airbag to the B-pillar.
(11) Disengage the lug that secures the side cur-
tain airbag bracket from within the bore in the roof
side rail and remove the unit from the vehicle (Fig.
49).
Fig. 45 A-Pillar Front Tether
1 - A-PILLAR
2 - FRONT TETHER
Fig. 46 Side Curtain Airbag Connector
1 - TIE WRAP
2 - B-PILLAR
3 - CONNECTOR
Fig. 47 Tether Anchor Screw
1 - A-PILLAR
2 - TETHER
3 - SCREW
Fig. 48 Side Curtain Airbag Screws
1 - SIDE CURTAIN AIRBAG
2 - REAR SCREW
3 - FRONT SCREW
VARESTRAINTS 8O - 37

INSTALLATION
The following procedure is for replacement of a
faulty or damaged side curtain airbag. If the airbag
is faulty or damaged, but not deployed, review the
recommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the side curtain airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deployment
before removing the airbag from the vehicle. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - SERVICE AFTER A SUPPLEMENTAL
RESTRAINT DEPLOYMENT).
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, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: To avoid personal injury or death, when
removing a deployed airbag, rubber gloves, eye
protection, and a long-sleeved shirt should be
worn. There may be deposits on the airbag unit and
other interior surfaces. In large doses, these depos-
its may cause irritation to the skin and eyes.WARNING: To avoid personal injury or death, use
extreme care to prevent any foreign material from
entering the side curtain airbag, or becoming
entrapped between the side curtain airbag cushion
and the roof rail garnish molding. Failure to
observe this warning could result in occupant inju-
ries upon airbag deployment.
(1) Position the side curtain airbag into the vehicle
as a unit.
(2) Engage the lug that secures the side curtain
airbag bracket into the bore in the roof side rail (Fig.
50).
(3) Install and tighten the screw that secures the
rear of the side curtain airbag to the B-pillar (Fig.
48). Tighten the screw to 23 N´m (17 ft. lbs.).
(4) Install and tighten the screw that secures the
front of the side curtain airbag to the A-pillar.
Tighten the screw to 9 N´m (80 in. lbs.).
(5) Install and tighten the screw that secures the
side curtain airbag front tether retainer to the base
of the A-pillar near the belt line (Fig. 47). Tighten
the screw to 5 N´m (44 in. lbs.).
(6) Install a new tie wrap to secure the side cur-
tain airbag pigtail wire to the inside of the B-pillar
(Fig. 46).
(7) Reconnect the pigtail wire connector for the
side curtain airbag to the vehicle wire harness con-
nector on the B-pillar. Be certain the connector is
fully engaged and latched.
(8) Reinstall the trim onto the A-pillar that con-
ceals the side curtain airbag front tether (Fig. 45).
Fig. 49 Side Curtain Airbag Remove
1 - ROOF SIDE RAIL
2 - SIDE CURTAIN AIRBAG
Fig. 50 Side Curtain Airbag Install
1 - ROOF SIDE RAIL
2 - BORE
3 - SIDE CURTAIN AIRBAG BRACKET
4 - LUG
8O - 38 RESTRAINTSVA

(9) Reinstall the grab handle onto the headliner.
(Refer to 23 - BODY/INTERIOR/ASSIST HANDLE -
INSTALLATION).
(10) Reinstall the trim onto the inside of the B-pil-
lar. (Refer to 23 - BODY/INTERIOR/B-PILLAR TRIM
- INSTALLATION).
(11) Reinstall the pinch welt to the front door
opening (Fig. 44).
(12) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
SIDE IMPACT SENSOR
DESCRIPTION
On vehicles equipped with the optional side curtain
airbags, two side impact sensors are used, one each
for the left and right sides of the vehicle (Fig. 51).
These sensors are mounted remotely from the bi-di-
rectional safing sensor that is internal to the Airbag
Control Module (ACM). The side impact sensors are
each secured with two screws to the forward vertical
surface of the right and left front door step wells and
concealed behind the step well trim paneling within
the passenger compartment.
The impact sensor housing has an integral connec-
tor receptacle and two integral mounting flanges, one
at the top and one at the bottom. An arrow on the
sensor housing provides a visual verification of the
proper orientation of the unit, and should always bepointed toward the outboard side of the vehicle. A
cavity in the center of the molded plastic impact sen-
sor housing contains the electronic circuitry of the
sensor, which includes an electronic communication
chip and an electronic impact sensor. Potting mate-
rial fills the cavity to seal and protect the internal
electronic circuitry and components. The side impact
sensors are each connected to the vehicle electrical
system through a dedicated take out and connector of
the vehicle wire harness.
The side impact sensors cannot be repaired or
adjusted and, if damaged or faulty, they must be
replaced.
OPERATION
The side impact sensors are electronic accelerome-
ters that sense the rate of vehicle deceleration, which
provides verification of the direction and severity of
an impact. Each sensor also contains an electronic
communication chip that allows the unit to commu-
nicate the sensor status as well as sensor fault infor-
mation to the microprocessor in the Airbag Control
Module (ACM). The ACM microprocessor continu-
ously monitors all of the passive restraint system
electrical circuits to determine the system readiness.
If the ACM detects a monitored system fault, it sets
a Diagnostic Trouble Code (DTC) and controls the
airbag indicator operation accordingly.
The impact sensors each receive battery current
and ground through dedicated left and right sensor
plus and minus circuits from the ACM. The impact
sensors and the ACM communicate by modulating
the voltage in the sensor plus circuit. The hard wired
circuits between the side impact sensors and the
ACM may be diagnosed and tested using conven-
tional diagnostic tools and procedures. However, con-
ventional diagnostic methods will not prove
conclusive in the diagnosis of the ACM or the impact
sensors. The most reliable, efficient, and accurate
means to diagnose the impact sensors, the ACM, and
the electronic message communication between the
sensors and the ACM requires the use of a diagnostic
scan tool. Refer to the appropriate diagnostic infor-
mation.
Fig. 51 Side Impact Sensor
1 - MOUNTING FLANGE (2)
2 - IMPACT SENSOR
3 - CONNECTOR RECEPTACLE
VARESTRAINTS 8O - 39

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, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: To avoid personal injury or death, never
strike or drop the side impact sensor, as it can
damage the impact sensor or affect its calibration.
The side impact sensor enables the system to
deploy the side curtain airbags. If an impact sensor
is accidentally dropped during service, the sensor
must be scrapped and replaced with a new unit.
Failure to observe this warning could result in acci-
dental, incomplete, or improper supplemental
restraint deployment.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the trim paneling from the interior of
the front door step well. (Refer to 23 - BODY/INTE-
RIOR/STEPWELL SCUFF PADS - REMOVAL).
(3) Disconnect the vehicle wire harness connector
from the side impact sensor connector receptacle
(Fig. 52).(4) Remove the two screws that secure the side
impact sensor to the forward vertical surface of the
step well.
(5) Remove the side impact sensor from the step
well.
INSTALLATION
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, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: To avoid personal injury or death, never
strike or drop the side impact sensor, as it can
damage the impact sensor or affect its calibration.
The side impact sensor enables the system to
deploy the side curtain airbags. If an impact sensor
is accidentally dropped during service, the sensor
must be scrapped and replaced with a new unit.
Failure to observe this warning could result in acci-
dental, incomplete, or improper supplemental
restraint deployment.
(1) Position the side impact sensor to the forward
vertical surface of the step well (Fig. 52). Be certain
Fig. 52 Side Impact Sensor Remove/Install
1 - SCREW (2)
2 - IMPACT SENSOR
3 - CONNECTOR
4 - STEP WELL
8O - 40 RESTRAINTSVA