Mercedes-Benz Sprinter / Dodge Sprinter. Manual - part 242

(6) Disconnect the two clockspring lower pigtail

connectors from the vehicle wire harness connectors
located between the steering column and the back of
the fuse block underneath the steering column (Fig.
16).

(7) Loosen the two screws that secure the clock-

spring to the multi-function switch housing far
enough to engage the clearance holes in the clock-
spring rotor and to disengage the clockspring case
from the switch housing.

(8) Remove the clockspring from the multi-function

switch housing. The clockspring cannot be repaired.
It must be replaced if faulty or damaged, or if the
driver airbag has been deployed.

(9) If the removed clockspring is to be reused, be

certain that the clockspring rotor is secured to the
clockspring case to maintain clockspring centering
until it is reinstalled on the steering column. If clock-
spring centering is not maintained, the clockspring
must be centered again before it is reinstalled. (Refer
to 8 - ELECTRICAL/RESTRAINTS/CLOCKSPRING -
STANDARD PROCEDURE - CLOCKSPRING CEN-
TERING).

INSTALLATION

The clockspring cannot be repaired. It must be

replaced if faulty or damaged, or if the driver airbag
has been deployed.

If the clockspring is not properly centered in rela-

tion to the steering wheel, steering shaft and steer-
ing

gear,

may

damaged.

(Refer

ELECTRICAL/RESTRAINTS/CLOCKSPRING

STANDARD PROCEDURE - CLOCKSPRING CEN-
TERING).

Service

replacement

clocksprings

are

shipped pre-centered and with the mounting screws
backed out from the case far enough to engage the
access holes in the upper surface of the rotor. The

clockspring mounting screws should not be tightened
into the clockspring case until the clockspring has
been installed on the steering column. If the screws
are tightened into or removed from the case before
the clockspring is installed on a steering column, the
clockspring centering procedure must be performed.

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.

NOTE: Before starting this procedure, be certain
that the front wheels are still in the straight-ahead
position.

(1) Carefully slide the centered clockspring down

over the steering column upper shaft until the screws
in the clockspring case are aligned with the mount-
ing holes on the multi-function switch housing.

(2) Tighten the two screws that secure the clock-

spring to the multi-function switch mounting hous-
ing. Tighten the screws to 2 N·m (18 in. lbs.).

(3) Reconnect the two clockspring lower pigtail

connectors to the vehicle wire harness connectors
located between the steering column and the back of
the fuse block underneath the steering column (Fig.
16).

(4) Route

the

clockspring

lower

pigtail

wires

around the lug on the bottom of the multi-function
switch housing and behind the fuse block underneath
the steering column (Fig. 17).

Fig. 16 Clockspring Remove/Install

1 - CLOCKSPRING
2 - SHROUD
3 - LOWER PIGTAIL CONNECTOR (2)

RESTRAINTS

8O - 15

(5) Reinstall the steering column opening cover

onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).

(6) Reinstall the steering wheel onto the steering

column. (Refer to 19 - STEERING/COLUMN/STEER-
ING WHEEL - INSTALLATION).

(7) Reconnect the clockspring upper pigtail wire

connectors to the terminals of the horn switch
located in the hub cavity of the steering wheel.

(8) Reinstall the driver airbag onto the steering

wheel. (Refer to 8 - ELECTRICAL/RESTRAINTS/
DRIVER AIRBAG - INSTALLATION).

DRIVER AIRBAG

DESCRIPTION

The color-keyed, injection molded, thermoplastic

driver airbag protective trim cover is the most visible
part of the driver airbag (Fig. 18). The driver airbag
is located in the center of the steering wheel, where
it is secured with two screws to the armature of the
horn switch within the hub cavity of the four-spoke
steering wheel. Concealed beneath the driver airbag
trim cover are the folded airbag cushion, the airbag
cushion retainer, the airbag housing, the airbag infla-
tor, and the retainers that secure the inflator to the
airbag housing (Fig. 19). The airbag cushion, hous-
ing, and inflator are secured within an integral
receptacle molded into the back of the trim cover.

Fig. 17 Clockspring Pigtail Routing

1 - MULTI-FUNCTION SWITCH
2 - FUSE BLOCK
3 - CLOCKSPRING LOWER PIGTAILS (2)

Fig. 18 Driver Airbag Trim Cover

1 - STEERING WHEEL
2 - TRIM COVER

8O - 16

RESTRAINTS

The airbag used in this model is a Next Genera-

tion-type that complies with revised federal airbag
standards to deploy with less force than those used
in some prior models. A radial deploying fabric cush-
ion with internal tethers is used. The airbag inflator
is a solid fuel, pyrotechnic-type unit with four studs
and is secured by four hex nuts to four studs on the
airbag cushion retainer ring to the back of the
stamped metal airbag housing. A keyed connector
receptacle on the driver airbag inflator connects the
inflator initiator to the vehicle electrical system
through a yellow-jacketed, two-wire pigtail harness of
the clockspring.

The driver airbag and trim cover unit cannot be

repaired, and must be replaced if deployed, faulty, or
in any way damaged.

OPERATION

The driver airbag is deployed by electrical signals

generated by the Airbag Control Module (ACM)
through the driver airbag squib circuit to the initia-
tor in the airbag inflator (Fig. 20). When the ACM
sends the proper electrical signal to the initiator the
electrical energy generates enough heat to initiate a
small pyrotechnic charge which, in turn, ignites
chemical pellets within the inflator. Once ignited,
these chemical pellets burn rapidly and produce a
large quantity of inert gas. The inflator is sealed to
the back of the airbag housing and a diffuser in the
inflator directs all of the inert gas into the airbag
cushion, causing the cushion to inflate. As the cush-
ion inflates, the driver airbag trim cover will split at
predetermined breakout lines, then fold back out of
the way. Following an airbag deployment, the airbag
cushion quickly deflates by venting the inert gas
towards the instrument panel through filtered vents
within the fabric used to construct the back (steering
wheel side) panel of the airbag cushion.

Some of the chemicals used to create the inert gas

may be considered hazardous while in their solid
state before they are burned, but they are securely

Fig. 19 Driver Airbag Housing

1 - HOUSING
2 - INFLATOR
3 - CONNECTOR RECEPTACLE
4 - TRIM COVER

Fig. 20 Driver Airbag Operation

1 - TRIM COVER
2 - INFLATOR
3 - INITIATOR
4 - CUSHION (FOLDED)
5 - STEERING WHEEL

RESTRAINTS

8O - 17

sealed within the airbag inflator. Typically, all poten-
tially hazardous chemicals are burned during an air-
bag deployment event. The inert gas that is produced
when the chemicals are burned is harmless. How-
ever, a small amount of residue from the burned
chemicals may cause some temporary discomfort if it
contacts the skin, eyes, or breathing passages. If skin
or eye irritation is noted, rinse the affected area with
plenty of cool, clean water. If breathing passages are
irritated, move to another area where there is plenty
of clean, fresh air to breath. If the irritation is not
alleviated by these actions, contact a physician.

REMOVAL

The following procedure is for replacement of a

faulty or damaged driver airbag. If the airbag is
faulty or damaged, but not deployed, review the rec-
ommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING

NON-DEPLOYED

SUPPLEMENTAL

RESTRAINTS).

the

driver

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

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 cushion
and other interior surfaces. In large doses, these
deposits may cause irritation to the skin and eyes.

(1) Disconnect and isolate the battery negative

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

(2) From the underside of the steering wheel,

remove the two screws that secure the driver airbag
to the horn switch armature within the hub cavity of
the steering wheel (Fig. 21).

8O - 18

RESTRAINTS

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