Mercedes-Benz Sprinter / Dodge Sprinter. Manual — part 248

(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 be

pointed 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

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RESTRAINTS

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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

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RESTRAINTS

VA

that the arrow on the sensor housing is pointed
toward the outboard side of the vehicle.

(2) Install and tighten the two screws that secure

the side impact sensor to the step well.

(3) Reconnect the vehicle wire harness connector

for the side impact sensor to the sensor connector
receptacle.

(4) Reinstall the trim paneling to the interior of

the front door step well. (Refer to 23 - BODY/INTE-
RIOR/STEPWELL SCUFF PADS - INSTALLATION).

(5) 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).

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RESTRAINTS

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