2006 MERCEDES-BENZ SPRINTER battery replacement

inflator directs all of the inert gas into the airbag
cushion, causing the cushion to inflate.
As the airbag cushion inflates, the passenger air-
bag door will unsnap from the clips that retain it to
the instrument panel at the top and bottom, then
pivot towards the top of the instrument panel and
out of the way on the woven straps. Following a pas-
senger airbag deployment, the airbag cushion quickly
deflates by venting the inert gas through the loose
weave of the fabric used to construct the back
(instrument panel side) 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
sealed within the airbag inflator. However, the gas
that is produced when the chemicals are burned is
harmless. 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 noticed, rinse the affected area
with plenty of cool, clean water. If breathing pas-
sages 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
immediately.
REMOVAL
The following procedure is for replacement of a
faulty or damaged passenger 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). If the passenger 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, eyeprotection, 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.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the instrument panel top cover tray
from over the passenger airbag (Fig. 29). (Refer to 23
- BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - TRAY - REMOVAL).
VARESTRAINTS 8O - 25

straight out from the inflator to disconnect it from
the receptacle.
(7) Remove the passenger airbag and airbag door
from the instrument panel as a unit.
INSTALLATION
The following procedure is for replacement of a
faulty or damaged passenger 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). If the passenger 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, use
extreme care to prevent any foreign material from
entering the passenger airbag, or becoming
entrapped between the passenger airbag cushion
and the passenger airbag door. Failure to observe
this warning could result in occupant injuries upon
airbag deployment.
WARNING: To avoid personal injury or death, the
passenger airbag door must never be painted.
Replacement passenger airbags are serviced with
doors in the original colors. Paint may change the
way in which the material of the airbag door
responds to an airbag deployment. Failure to
observe this warning could result in occupant inju-
ries upon airbag deployment.
(1) Carefully position the passenger airbag and
airbag door unit to the instrument panel (Fig. 29).
(2) When installing the passenger airbag, recon-
nect the vehicle wire harness connector to the airbag
inflator connector receptacle by pressing straight in
on the connector. You can be certain that the connec-tor is fully engaged by listening carefully for a dis-
tinct, audible click as the connector snaps into place.
(3) Push the passenger airbag unit forward far
enough to engage the lower edge of the airbag door
with the two lower clips in the instrument panel.
(4) Install and tighten the two screws that secure
the flange of the passenger airbag housing to the
bracket on the instrument panel structural support.
Tighten the screws to 10 N´m (89 in. lbs.).
(5) Install and tighten the two screws that secure
the passenger airbag door upper clips to the instru-
ment panel base trim. Tighten the screws to 2 N´m
(18 in. lbs.).
(6) Reinstall the instrument panel top cover tray
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/INSTRUMENT PANEL TOP
COVER - TRAY - INSTALLATION).
(7) 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).
PASSENGER AIRBAG
BRACKET
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.
(1) Remove the passenger airbag from the instru-
ment panel. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/PASSENGER AIRBAG - REMOVAL).
(2) Remove the four screws that secure the passen-
ger airbag bracket to the instrument panel structural
support (Fig. 30).
VARESTRAINTS 8O - 27

(3) Remove the passenger airbag bracket from the
instrument panel structural support.
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.
(1) Position the passenger airbag bracket onto the
instrument panel structural support (Fig. 30).
(2) Install and tighten the four screws that secure
the passenger airbag bracket to the instrument panel
structural support. Tighten the screws to 10 N´m (89
in. lbs.).
(3) Reinstall the passenger airbag into the instru-
ment panel. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/PASSENGER AIRBAG -
INSTALLATION).
REAR SEAT BELT & RETRAC-
TOR
REMOVAL
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) Remove the rear bench seat containing the rear
seat belt and retractor unit to be serviced from the
vehicle.
(2) Lift the seat belt webbing to access and remove
the plastic push pin fastener that secures the rear
seat belt turning loop trim cover to the turning loop
bracket at the top of the seat back (Fig. 31).
(3) Remove the turning loop trim cover from the
turning loop bracket.
(4) Remove the push nut at the back of the turn-
ing loop bracket that secures the pin on which the
two turning loops pivot (Fig. 32).
Fig. 30 Passenger Airbag Bracket Remove/Install
1 - BRACKET
2 - STRUCTURAL SUPPORT
3 - SCREW (4)
Fig. 31 Turning Loop Trim Cover
1 - TRIM COVER
2 - SEAT BELT
3 - RETAINER
4 - REAR SEAT BACK
8O - 28 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

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

RAIN SENSOR
DESCRIPTION
The rain sensor provides the primary input for the
optional automatic wiper system (Fig. 6). The rain
sensor is located on the inside of the windshield,
where it is concealed within the molded plastic trim
cover that snaps over the base of the rear view mir-
ror arm. The sensor fits within the center of a ring-
like molded plastic bracket that is glued to the inside
of the windshield glass and that also serves as the
support for the rear view mirror.
The rain sensor is contained within a circular
molded black plastic housing with a short pigtail
wire and a connector insulator containing three ter-
minal cavities that exits one side of the housing. This
pigtail connects the rain sensor to the vehicle electri-
cal system through a dedicated take out and connec-
tor of the overhead wire harness that extends from
above the headliner. A molded plastic trough routes
and conceals the pigtail wires on the inside of the
windshield between the rear view mirror base and
the headliner.
The windshield side of the rain sensor housing is
open, but covered with a clear gelatin-like material
that protects the internal electronic sensor circuitry
and serves as the lens for the InfraRed (IR) diodes
and photocells within the sensor housing. This gel
coating must never be touched or the rain sensor
function may be impaired and the unit rendered
unusable. The rain sensor cannot be adjusted or
repaired and, if damaged or faulty, the entire sensor
must be replaced. The sensor bracket and a rear viewmirror adhesive kit are available for separate service
replacement.
OPERATION
The rain sensor operates on battery current and a
clean ground received from the rain sensor control
module. The rain sensor contains InfraRed (IR)
diodes that direct IR light beams at the windshield
at an angle. When the windshield glass is dry, most
of this IR light is reflected back to the sensor, which
uses photocell receivers to measure the intensity of
the light. When moisture accumulates on the wind-
shield glass, much of the IR light is refracted away
from the photocell receivers. This causes changes in
the signal output of the rain sensor. The rain sensor
control module monitors the signal output from the
sensor and then controls the wiper motor speed and
wipe intervals accordingly.
It is important to note that the default condition
for the wiper system is automatic wipers Off; there-
fore, if no message is received from the rain sensor
by the rain sensor control module, the automatic wip-
ers will be disabled. If automatic wipers are disabled,
normal low and high speed continuous wiper opera-
tion are unaffected. Also, due to the low voltage
nature of the rain sensor signal and the impact that
minor fluctuations in this signal strength can have
on wiper operation, grounded shielding circuits are
provided at the roof and control module connectors to
control electrical induction into the sensor signal cir-
cuit.
The hard wired rain sensor circuits may be diag-
nosed using conventional diagnostic tools and meth-
ods. However, conventional diagnostic methods may
not prove conclusive in the diagnosis of the internal
circuitry or the optics of the rain sensor. Refer to the
appropriate wiring information.
STANDARD PROCEDURE
RAIN SENSOR BRACKET REPLACEMENT
The rain sensor fits within the center of a ring-like
molded plastic bracket that is glued to the inside of
the windshield glass and that also serves as the sup-
port for the rear view mirror arm. If the bracket
should come loose from the windshield, it must be
reinstalled using a rear view mirror adhesive kit and
the procedure that follows.
Fig. 6 Rain Sensor
1 - HEADLINER
2 - TROUGH
3 - WINDSHIELD
4 - RAIN SENSOR
5 - MIRROR
8R - 12 WIPERS/WASHERSVA