1998 DODGE RAM 1500 Removal

(6) Remove the seat belt turning loop from the
upper inner C-pillar.
(7) Remove the upper and lower trim from the
inner C-pillar. (Refer to 23 - BODY/INTERIOR/C-
PILLAR UPPER TRIM - REMOVAL) and (Refer to
23 - BODY/INTERIOR/C-PILLAR LOWER TRIM -
REMOVAL).
(8) Remove the screw that secures the seat belt
web guide to the inner C-pillar near the belt line.
(9) Remove the seat belt web guide from the inner
C-pillar.
(10) Remove the screw that secures the lower
retractor bracket to the lower inner C-pillar below
the retractor mounting hole.
(11) Disengage the hook on the upper retractor
bracket from the slot in the lower inner C-pillar
above the retractor mounting hole.
(12) Remove the rear outboard seat belt and
retractor from the retractor mounting hole in the
lower inner C-pillar.
INSTALLATION
The only component of this seat belt and retractor
unit that is available for individual service replace-
ment is the plastic web stop button that prevents the
latch plate from falling to the floor while in the
stored position. Refer to the instructions supplied
with the service kit for the proper web stop button
replacement procedures.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, DURING AND FOLLOWING ANY SEAT BELT
OR CHILD RESTRAINT ANCHOR SERVICE, CARE-
FULLY INSPECT ALL SEAT BELTS, BUCKLES,
MOUNTING HARDWARE, RETRACTORS, TETHER
STRAPS, AND ANCHORS FOR PROPER INSTALLA-
TION, OPERATION, 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. REPLACE ANY CHILD
RESTRAINT ANCHOR OR THE UNIT TO WHICH THE
ANCHOR IS INTEGRAL THAT HAS BEEN BENT OR
DAMAGED. NEVER ATTEMPT TO REPAIR A SEAT
BELT OR CHILD RESTRAINT COMPONENT.
ALWAYS REPLACE DAMAGED OR FAULTY SEAT
BELT AND CHILD RESTRAINT COMPONENTS WITH
THE CORRECT, NEW AND UNUSED REPLACEMENT
PARTS LISTED IN THE DAIMLERCHRYSLER MOPAR
PARTS CATALOG.
(1) Position the rear outboard seat belt and retrac-
tor to the retractor mounting hole in the lower inner
C-pillar (Fig. 43).
(2) Engage the hook on the upper retractor bracket
into the slot in the lower inner C-pillar above the
retractor mounting hole.
(3) Install and tighten the screw that secures the
lower retractor bracket to the lower inner C-pillar
below the retractor mounting hole. Tighten the screw
to 40 N´m (29 ft. lbs.).
(4) Position the seat belt web guide to the inner
C-pillar near the belt line.
(5) Install and tighten the screw that secures the
seat belt web guide to the inner C-pillar. Tighten the
screw to 2 N´m (20 in. lbs.).
(6) Reinstall the upper and lower trim onto the
inner C-pillar. (Refer to 23 - BODY/INTERIOR/C-
PILLAR UPPER TRIM - INSTALLATION) and
(Refer to 23 - BODY/INTERIOR/C-PILLAR LOWER
TRIM - INSTALLATION).
(7) Position the seat belt turning loop onto the
upper inner C-pillar.
Fig. 43 Rear Outboard Seat Belt & Retractor
Remove/Install
1 - C-PILLAR
2 - TRIM PANEL
3 - TURNING LOOP
4 - SCREW
5 - TRIM COVER
6 - SEAT BELT
7 - SCREW
8 - LOWER ANCHOR
9 - SCREW
10 - SCREW
11 - RETRACTOR
12 - WEB GUIDE
DRRESTRAINTS 8O - 47
REAR OUTBOARD SEAT BELT & RETRACTOR (Continued)

(8) Install and tighten the screw that secures the
seat belt turning loop to the C-pillar. Tighten the
screw to 40 N´m (29 ft. lbs.).
(9) Engage the lower snap features of the new trim
cover over the rear outboard seat belt turning loop
and, using hand pressure, press firmly and evenly on
the top of the trim cover until it snaps into place.
(10) Position the lower seat belt anchor to the base
of the inner C-pillar.
(11) Install and tighten the screw that secures the
lower seat belt anchor to the base of the inner C-pil-
lar. Tighten the screw to 40 N´m (29 ft. lbs.).
(12) Reinstall the rear seat into the vehicle. (Refer
to 23 - BODY/SEATS/SEAT - REAR - INSTALLA-
TION).
REAR SEAT BELT BUCKLE
REMOVAL
REMOVAL - CENTER & LEFT OUTBOARD
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, DURING AND FOLLOWING ANY SEAT BELT
OR CHILD RESTRAINT ANCHOR SERVICE, CARE-
FULLY INSPECT ALL SEAT BELTS, BUCKLES,
MOUNTING HARDWARE, RETRACTORS, TETHER
STRAPS, AND ANCHORS FOR PROPER INSTALLA-
TION, OPERATION, 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. REPLACE ANY CHILD
RESTRAINT ANCHOR OR THE UNIT TO WHICH THE
ANCHOR IS INTEGRAL THAT HAS BEEN BENT OR
DAMAGED. NEVER ATTEMPT TO REPAIR A SEAT
BELT OR CHILD RESTRAINT COMPONENT.
ALWAYS REPLACE DAMAGED OR FAULTY SEAT
BELT AND CHILD RESTRAINT COMPONENTS WITH
THE CORRECT, NEW AND UNUSED REPLACEMENT
PARTS LISTED IN THE DAIMLERCHRYSLER MOPAR
PARTS CATALOG.(1) Lift up the rear seat cushion into its stowed
position against the rear seat back.
(2) Remove the screw that secures either the cen-
ter or the left outboard occupant buckle unit to the
rear floor panel near the base of the cab back panel
(Fig. 44). On models with the optional 60/40 split
rear bench, the screw that secures the buckle unit
also secures one of the rear seat mounting brackets
to the rear floor panel.
(3) Remove the center or the left outboard occu-
pant buckle unit from the rear floor panel or from
the rear seat mounting bracket.
Fig. 44 Rear Seat Belt Buckle Remove/Install
1 - CAB BACK PANEL
2 - CENTER SEAT BELT RETRACTOR
3 - SCREW (4)
4 - LEFT OUTBOARD OCCUPANT BUCKLE UNIT
5 - CENTER OCCUPANT BUCKLE UNIT
6 - CENTER ANCHOR/RIGHT OUTBOARD OCCUPANT BUCKLE
& BRACKET UNIT
7 - REAR FLOOR PANEL
8O - 48 RESTRAINTSDR
REAR OUTBOARD SEAT BELT & RETRACTOR (Continued)

REMOVAL - CENTER ANCHOR & RIGHT
OUTBOARD
The unique black, keyed center seat belt lower
anchor buckle and the right outboard occupant
buckle are serviced as a unit with their mounting
bracket. The rear center seat belt retractor is also
secured to the mounting bracket with these two
buckles, but can be removed from the mounting
bracket and is serviced separately from the two buck-
les. (Refer to 8 - ELECTRICAL/RESTRAINTS/REAR
CENTER SEAT BELT & RETRACTOR - REMOVAL).
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, DURING AND FOLLOWING ANY SEAT BELT
OR CHILD RESTRAINT ANCHOR SERVICE, CARE-
FULLY INSPECT ALL SEAT BELTS, BUCKLES,
MOUNTING HARDWARE, RETRACTORS, TETHER
STRAPS, AND ANCHORS FOR PROPER INSTALLA-
TION, OPERATION, 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. REPLACE ANY CHILD
RESTRAINT ANCHOR OR THE UNIT TO WHICH THE
ANCHOR IS INTEGRAL THAT HAS BEEN BENT OR
DAMAGED. NEVER ATTEMPT TO REPAIR A SEAT
BELT OR CHILD RESTRAINT COMPONENT.
ALWAYS REPLACE DAMAGED OR FAULTY SEAT
BELT AND CHILD RESTRAINT COMPONENTS WITH
THE CORRECT, NEW AND UNUSED REPLACEMENT
PARTS LISTED IN THE DAIMLERCHRYSLER MOPAR
PARTS CATALOG.
(1) Reach between the rear seat cushion and the
rear seat back to access and unbuckle the rear center
seat belt lower anchor latch plate from the unique
black, keyed lower anchor buckle. Use an ignition
key or a small screwdriver to depress the small white
release button on the anchor buckle.
(2) Remove the rear seat from the vehicle. On
models with the optional 60/40 split rear bench, only
the 60 percent section (right side) of the rear seat
must be removed. (Refer to 23 - BODY/SEATS/SEAT
- REAR - REMOVAL).(3) Remove the screw that secures the rear center
seat belt retractor to the center anchor/right out-
board occupant buckle and mounting bracket unit on
the rear floor panel near the cab back panel (Fig. 45).
(4) Remove the rear center seat belt retractor from
the center anchor/right outboard occupant buckle and
mounting bracket unit.
(5) Remove the two screws that secure the center
anchor/right outboard occupant buckle and mounting
bracket unit to the rear floor panel near the base of
the cab back panel (Fig. 46).
(6) Remove the center anchor/right outboard occu-
pant buckle and mounting bracket unit from the rear
floor panel.
Fig. 45 Rear Center Retractor & Mounting Bracket
1 - RIGHT OUTBOARD OCCUPANT BUCKLE
2 - REAR CENTER SEAT BELT
3 - REAR CENTER SEAT BELT RETRACTOR
4 - MOUNTING BRACKET
5 - CENTER ANCHOR BUCKLE
6 - SCREW (1)
DRRESTRAINTS 8O - 49
REAR SEAT BELT BUCKLE (Continued)

retracted or extracted is a sure indication that the
seat belt tensioner has been deployed and requires
replacement. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/FRONT OUTBOARD SEAT BELT &
RETRACTOR - REMOVAL).
OPERATION
The seat belt tensioners are deployed 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. When the ACM
sends the proper electrical signal to the tensioners,
the electrical energy generates enough heat to ini-
tiate a small pyrotechnic gas generator. The gas gen-
erator is installed at the top of the tensioner housing
which contains a long metal tape that is routed
through two chambers within the housing. Each end
of the tape is wound around the outer sleeve of a
mechanical clutch mechanism secured to one end of
the torsion bar upon which the retractor spool is
secured. As the gas expands, it is directed against
the metal tape within the two chambers of the hous-
ing causing the tape to unwind from the clutch
sleeve. As the clutch rotates it engages the torsion
bar, which drives the seat belt retractor spool causing
the slack to be removed from the seat belt.
Once a seat belt tensioning sequence has been
completed, the forward momentum of the occupant
results in deformation of the torsion bar. As the tor-
sion bar deforms it allows the seat belt webbing to
unwind from the retractor spool, which causes the
metal tape to be wound back onto the clutch sleeve
until it is pulled tight against two cutter blades
within the housing, which immediately cut the metal
tape.
Removing excess slack from the seat belt not only
keeps the occupant properly positioned for an airbag
deployment following a frontal impact of the vehicle,
but also helps to reduce injuries that the occupant
might experience in these situations as a result of a
harmful contact with the steering wheel, steering col-
umn, instrument panel and/or windshield. The tor-
sion bar is designed to deform in order to control the
loading being applied to the occupant by the seat belt
during a frontal impact, further reducing the poten-
tial 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 DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
SEAT BELT TENSION
REDUCER
DESCRIPTION
A seat belt tension reducer is standard equipment
for the driver side front outboard seat belt on stan-
dard cab versions of this model (Fig. 49). The tension
reducer is integral to the driver side front outboard
seat belt and retractor unit, which is secured to the
inner B-pillar on the left side of the vehicle. The
retractor is concealed beneath the molded plastic
inner B-pillar trim. The seat belt tension reducer
consists primarily of a 12-volt Direct Current (DC)
solenoid and an integral connector receptacle that is
located on the forward facing end housing of the
retractor. The seat belt tension reducer is controlled
by a battery current output of the ignition switch and
a ground path provided by the seat belt switch, and
is connected to the vehicle electrical system through
a dedicated take out of the body wire harness by a
keyed and latching molded plastic connector insula-
tor to ensure a secure connection.
The seat belt tension reducer cannot be repaired
and, if faulty or damaged, the entire driver side front
outboard seat belt and retractor unit must be
replaced. (Refer to 8 - ELECTRICAL/RESTRAINTS/
FRONT OUTBOARD SEAT BELT & RETRACTOR -
REMOVAL).
Fig. 49 Seat Belt Tension Reducer
1 - TENSIONER HOUSING OR CHAMBER
2 - GAS GENERATOR
3 - TENSIONER PIGTAIL WIRE
4 - SPOOL
5 - TENSION REDUCER (DRIVER SIDE ON STANDARD CAB
ONLY)
6 - REDUCER CONNECTOR RECEPTACLE
DRRESTRAINTS 8O - 53
SEAT BELT TENSIONER (Continued)

SEAT BELT TURNING LOOP
ADJUSTER
REMOVAL
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, DURING AND FOLLOWING ANY SEAT BELT
OR CHILD RESTRAINT ANCHOR SERVICE, CARE-
FULLY INSPECT ALL SEAT BELTS, BUCKLES,
MOUNTING HARDWARE, RETRACTORS, TETHER
STRAPS, AND ANCHORS FOR PROPER INSTALLA-
TION, OPERATION, 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. REPLACE ANY CHILD
RESTRAINT ANCHOR OR THE UNIT TO WHICH THE
ANCHOR IS INTEGRAL THAT HAS BEEN BENT OR
DAMAGED. NEVER ATTEMPT TO REPAIR A SEAT
BELT OR CHILD RESTRAINT COMPONENT.
ALWAYS REPLACE DAMAGED OR FAULTY SEAT
BELT AND CHILD RESTRAINT COMPONENTS WITH
THE CORRECT, NEW AND UNUSED REPLACEMENT
PARTS LISTED IN THE DAIMLERCHRYSLER MOPAR
PARTS CATALOG.
(1) Unsnap and remove the trim cover from the
front outboard seat belt turning loop to access the
screw that secures the turning loop to the height
adjuster on the upper inner B-pillar. Discard the
removed turning loop trim cover as it is not intended
for reuse.
(2) Remove the screw that secures the seat belt
turning loop to the height adjuster.
(3) Remove the front seat belt turning loop from
the height adjuster.
(4) Remove the upper trim from the inner B-pillar.
(Refer to 23 - BODY/INTERIOR/B-PILLAR UPPER
TRIM - REMOVAL).
(5) Loosen the two screws that secure the seat belt
turning loop height adjuster far enough to remove
the adjuster from the upper B-pillar (Fig. 50).
(6) Disengage the tab near the lower end of the
seat belt turning loop height adjuster from the slot in
the sheet metal and remove the adjuster from the
inner B-pillar.
INSTALLATION
WARNING: TO AVOID PERSONAL INJURY OR DEATH,
DURING AND FOLLOWING ANY SEAT BELT OR
CHILD RESTRAINT ANCHOR SERVICE, CAREFULLY
INSPECT ALL SEAT BELTS, BUCKLES, MOUNTING
HARDWARE, RETRACTORS, TETHER STRAPS, AND
ANCHORS FOR PROPER INSTALLATION, OPERA-
TION, OR DAMAGE. REPLACE ANY BELT THAT IS
CUT, FRAYED, OR TORN. STRAIGHTEN ANY BELT
THAT IS TWISTED. TIGHTEN ANY LOOSE FASTEN-
ERS. REPLACE ANY BELT THAT HAS A DAMAGED
OR INOPERATIVE BUCKLE OR RETRACTOR.
REPLACE ANY BELT THAT HAS A BENT OR DAM-
AGED LATCH PLATE OR ANCHOR PLATE. REPLACE
ANY CHILD RESTRAINT ANCHOR OR THE UNIT TO
WHICH THE ANCHOR IS INTEGRAL THAT HAS BEEN
BENT OR DAMAGED. NEVER ATTEMPT TO REPAIR A
SEAT BELT OR CHILD RESTRAINT COMPONENT.
ALWAYS REPLACE DAMAGED OR FAULTY SEAT
BELT AND CHILD RESTRAINT COMPONENTS WITH
THE CORRECT, NEW AND UNUSED REPLACEMENT
PARTS LISTED IN THE DAIMLERCHRYSLER MOPAR
PARTS CATALOG.
(1) Position the front seat belt turning loop
adjuster to the inner B-pillar (Fig. 50).
(2) Engage the tab near the lower end of the seat
belt turning loop height adjuster into the slot in the
sheet metal of the inner B-pillar.
(3) Hand tighten the lower of the two screws that
secure the seat belt turning loop height adjuster to
the upper B-pillar far enough to keep the tab on the
lower end of the adjuster engaged in the B-pillar slot.
Fig. 50 Seat Belt Turning Loop Adjuster Remove/
Install
1 - B-PILLAR
2 - ADJUSTER
3 - SCREW (2)
4 - GRAB HANDLE BRACKET (QUAD CAB ONLY)
DRRESTRAINTS 8O - 55

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 drop down
from the roof rail between the edge of the headliner
and the side glass/body pillars to form a curtain-like
cushion to protect the vehicle occupants during a side
impact collision. The front tether keeps the front por-
tion 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 SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (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 DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.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 DEPOSITS 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 HEADLINER. FAILURE TO OBSERVE THIS
WARNING COULD RESULT IN OCCUPANT INJURIES
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 headliner from the vehicle. (Refer
to 23 - BODY/INTERIOR/HEADLINER -
REMOVAL).
(3) Remove the screw that secures the side curtain
airbag tether retainer to the base of the A-pillar near
the belt line (Fig. 53).
(4) Disengage the two side curtain airbag tether
plastic retainer clips from the A-pillar.
Fig. 53 Side Curtain Airbag Remove/Install - Typical
1 - ROOF SIDE RAIL
2 - SPRING NUT (4 - STD CAB/6 - QUAD CAB)
3 - SCREW (4 - STD CAB/6 - QUAD CAB)
4 - CLIP (2)
5 - RIVET NUT
6 - SCREW
7 - SIDE CURTAIN AIRBAG
8 - RETAINER (3 - STD CAB/5 - QUAD CAB)
9 - WIRE HARNESS CONNECTOR
DRRESTRAINTS 8O - 57
SIDE CURTAIN AIRBAG (Continued)

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. 54).
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
secured within the right and left B-pillars just above
the front seat belt retractors and behind the lower
B-pillar trim in the passenger compartment.
The impact sensor housing has an integral connec-
tor receptacle, an integral mounting stud, and an
integral locating tab. A cavity in the center of the
molded black plastic impact sensor housing contains
the electronic circuitry of the sensor, which includes
an electronic communication chip and an electronic
impact sensor. Potting material fills the cavity to seal
and protect the internal electronic circuitry and com-
ponents. The side impact sensors are each connected
to the vehicle electrical system through a dedicated
take out and connector of the body 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 DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
REMOVAL - STANDARD CAB
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (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 DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
Fig. 54 Side Impact Sensor
1 - SENSOR
2 - CONNECTOR RECEPTACLE
3 - STUD
DRRESTRAINTS 8O - 59

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 MODULE MUST BE
SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER SUPPLEMENTAL RESTRAINT DEPLOY-
MENT.
(1) Adjust the front seat to its most forward posi-
tion for easiest access to the lower B-pillar trim.
(2) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(3) Remove the front outboard seat belt and retrac-
tor from the inside of the B-pillar. (Refer to 8 -
ELECTRICAL/RESTRAINTS/FRONT OUTBOARD
SEAT BELT & RETRACTOR - REMOVAL - STAN-
DARD CAB).
(4) Remove the nut that secures the side impact
sensor stud to the inner B-pillar (Fig. 55).(5) Reach through the retractor mounting hole in
the inner B-pillar to access the side impact sensor
and disengage the locating pin and mounting stud
from the holes in the inner B-pillar.
(6) Pull the side impact sensor out of the B-pillar
far enough to access and disconnect the body wire
harness connector for the sensor from the sensor con-
nector receptacle.
(7) Remove the side impact sensor from the B-pil-
lar.
REMOVAL - QUAD CAB
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (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 DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
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 MODULE MUST BE
SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER SUPPLEMENTAL RESTRAINT DEPLOY-
MENT.
(1) Adjust the front seat to its most forward posi-
tion for easiest access to the lower B-pillar trim.
(2) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(3) Remove the nut that secures the side impact
sensor stud to the inner B-pillar (Fig. 56).
(4) Reach through the large hole above the retrac-
tor mounting hole in the inner B-pillar to access the
side impact sensor and disengage the locating pin
and mounting stud from the holes in the inner B-pil-
lar.
Fig. 55 Side Impact Sensor Remove/Install -
Standard Cab
1 - SIDE IMPACT SENSOR
2 - WIRE HARNESS CONNECTOR
3 - B-PILLAR
4 - NUT
8O - 60 RESTRAINTSDR
SIDE IMPACT SENSOR (Continued)