1998 DODGE RAM 1500 4 wheel drive

no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.(2) Remove the Power Distribution Center (PDC)
cover.
(3) Remove the park lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the PDC.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Position the park lamp relay to the proper
receptacle in the Power Distribution Center (PDC).
(2) Align the park lamp relay terminals with the
terminal cavities in the PDC.
(3) Press firmly and evenly on the top of the park
lamp relay until the terminals are fully seated in the
PDC.
(4) Install the PDC cover.
(5) Reconnect the battery negative cable.
PARK/TURN SIGNAL LAMP
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the headlamp unit.(Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - REMOVAL).
(3) Remove the bulb socket from the headlamp
unit.
(4) Release the front park/turn signal bulb locking
tabs and remove the bulb from the socket (Fig. 19).
INSTALLATION
(1) Install the front park/turn signal bulb into the
bulb socket.
(2) Install the bulb socket into the headlamp unit.
(3) Install the headlamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - INSTALLATION).
Fig. 18 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
DRLAMPS/LIGHTING - EXTERIOR 8L - 21
PARK LAMP RELAY (Continued)

SEAT BELT TENSION REDUCER
DESCRIPTION.........................53
OPERATION...........................54
DIAGNOSIS AND TESTING - SEAT BELT
TENSION REDUCER...................54
SEAT BELT TURNING LOOP ADJUSTER
REMOVAL.............................55
INSTALLATION.........................55
SIDE CURTAIN AIRBAG
DESCRIPTION.........................56
OPERATION...........................56REMOVAL.............................57
INSTALLATION.........................58
SIDE IMPACT SENSOR
DESCRIPTION.........................59
OPERATION...........................59
REMOVAL
REMOVAL - STANDARD CAB............59
REMOVAL - QUAD CAB................60
INSTALLATION
INSTALLATION - STANDARD CAB.........61
INSTALLATION - QUAD CAB.............61
RESTRAINTS
DESCRIPTION
An occupant restraint system is standard factory-
installed safety equipment on this model. Available
occupant restraints for this model include both active
and passive types. Active restraints are those which
require the vehicle occupants to take some action to
employ, such as fastening a seat belt; while passive
restraints require no action by the vehicle occupants
to be employed (Fig. 1).
ACTIVE RESTRAINTS
The active restraints for this model include:
²Front Seat Belts- Both outboard front seating
positions are equipped with three-point seat belt sys-
tems employing a lower B-pillar mounted inertia
latch-type emergency locking retractor, height-adjust-
able upper B-pillar mounted turning loops, a fixed
lower seat belt anchor secured to the lower B-pillar
(standard cab) or floor panel adjacent to the B-pillar
(quad cab), and a traveling end-release seat belt
buckle secured to the inboard seat track. The driver
side retractor for standard cab models includes an
electrically actuated seat belt tension reducer. The
passenger side front seat retractor for all models is
also switchable from an emergency locking retractor
to an automatic locking retractor. The front seat belt
buckle for the driver side of all models includes an
integral seat belt switch that detects whether its seat
belt has been fastened. The center front seating posi-
tion for standard cab models is also equipped with a
three-point seat belt employing a floor panel
mounted inertia latch-type retractor, a routing
bracket and bezel near the top of the cab back panel,
and two fixed end-release buckles secured to the cen-
ter seat cushion frame. The center front seating posi-
tion for quad cab models is equipped with a fixed lap
belt and an end-release buckle secured to the center
seat cushion frame.
²Rear Seat Belts- All three rear seating posi-
tions are equipped with three-point seat belt sys-
tems. The outboard seating position belts employ a
lower C-pillar mounted inertia latch-type emergencylocking retractor, a fixed position upper C-pillar
mounted turning loop, and a fixed lower seat belt
anchor secured to the lower C-pillar. The rear seat
center seating position belt has a rear floor panel
mounted inertia latch-type emergency locking retrac-
tor and a routing bracket and bezel on the top of the
cab back panel. The end-release buckle units for the
right outboard seating position and the center seat-
ing position lower anchor are integral to the center
retractor mounting bracket on the rear floor panel.
The end-release buckle units for the center and left
outboard seating positions are individually secured to
the rear floor panel on models with the standard
equipment rear bench seat, or secured with the rear
seat mounting hardware on models with the optional
60/40 split rear bench seat.
²Child Restraint Anchors- All standard cab
models are equipped with two, fixed-position, child
seat upper tether anchors that are integral to the
upper cab back panel reinforcement and concealed
behind individual trim cover and bezel units that are
integral to the cab back trim panel. All quad cab
models are equipped with three child seat upper
tether anchor straps that are secured to the upper
cab back panel reinforcement, behind the upright
rear seat back. Two lower anchors are also provided
for the front outboard seating position of standard
cab models, and for each rear outboard seating posi-
tion on quad cab models. These lower anchors are
accessed from the front of the seat where the seat
back meets the seat cushion. The child seat tether
and lower anchors for the front seat are deleted on
quad cab models.
PASSIVE RESTRAINTS
The passive restraints available for this model
include the following:
²Dual Front Airbags- Multistage driver and
front passenger airbags are available for this model.
This airbag system is a passive, inflatable, Supple-
mental Restraint System (SRS) and vehicles with
this equipment can be readily identified by the ªSRS
- AIRBAGº logo molded into the driver airbag trim
cover in the center of the steering wheel and also
8O - 2 RESTRAINTSDR

²Airbag Indicator- The airbag indicator is inte-
gral to the ElectroMechanical Instrument Cluster
(EMIC), which is located on the instrument panel in
front of the driver.
²Clockspring- The clockspring is located near
the top of the steering column, directly beneath the
steering wheel.
²Driver Airbag- The driver airbag is located in
the center of the steering wheel, beneath the driver
airbag trim cover.
²Driver Knee Blocker- The driver knee blocker
is a structural unit secured to the back side of and
integral to the instrument panel steering column
opening cover.
²Passenger Airbag- The passenger airbag is
located on the instrument panel, beneath the passen-
ger airbag door on the instrument panel above the
glove box on the passenger side of the vehicle.
²Passenger Airbag On/Off Switch- Standard
cab models without a rear seat are equipped with a
passenger airbag on/off switch, which is located on
the right side of the instrument panel center bezel.
²Passenger Knee Blocker- The passenger knee
blocker is a structural reinforcement that is integral
to and concealed within the glove box door.
²Seat Belt Tensioner- The seat belt tensioner
is integral to the front outboard seat belt retractor
units on vehicles equipped with dual front airbags.
²Side Impact Sensor- Two side impact sensors
are used on vehicles equipped with the optional side
curtain airbags, one left side and one right side. One
sensor is located behind the B-pillar trim near the
base of each B-pillar.
²Side Curtain Airbag- In vehicles equipped
with this option, a side curtain airbag is located on
each inside roof side rail above the headliner, and
extends from the A-pillar to the B-pillar on standard
cab models, and from the A-pillar to the C-pillar on
quad cab models.The ACM and the EMIC each contain a central
processing unit and programming that allow them to
communicate with each other using the Programma-
ble Communications Interface (PCI) data bus net-
work. This method of communication is used by the
ACM for control of the airbag indicator on all models
equipped with dual front airbags. (Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/
COMMUNICATION - DESCRIPTION).
Hard wired circuitry connects the supplemental
restraint system components to each other through
the electrical system of the vehicle. These hard wired
circuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained by
many different methods. These circuits may be con-
nected to each other, to the vehicle electrical system,
and to the supplemental restraint system compo-
nents through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
OPERATION
ACTIVE RESTRAINTS
The primary passenger restraints in this or any
other vehicle are the standard equipment factory-in-
stalled seat belts and child restraint anchors. Seat
belts and child restraint anchors are referred to as
an active restraint because the vehicle occupants are
required to physically fasten and properly adjust
these restraints in order to benefit from them. See
the owner's manual in the vehicle glove box for more
information on the features, use and operation of all
of the factory-installed active restraints.
PASSIVE RESTRAINTS
The passive restraints are referred to as a supple-
mental restraint system because they were designed
and are intended to enhance the protection for the
occupants of the vehicleonlywhen used in conjunc-
tion with the seat belts. They are referred to as pas-
sive restraints because the vehicle occupants are not
required to do anything to make them operate; how-
ever, the vehicle occupants must be wearing their
seat belts in order to obtain the maximum safety
benefit from the factory-installed supplemental
restraint system.
The supplemental restraint system electrical cir-
cuits are continuously monitored and controlled by a
microprocessor and software contained within the
Fig. 2 SRS Logo
8O - 4 RESTRAINTSDR
RESTRAINTS (Continued)

Airbag Control Module (ACM). An airbag indicator in
the ElectroMechanical Instrument Cluster (EMIC)
illuminates for about six seconds as a bulb test each
time the ignition switch is turned to the On or Start
positions. Following the bulb test, the airbag indica-
tor is turned on or off by the ACM to indicate the
status of the supplemental restraint system. If the
airbag indicator comes on at any time other than
during the bulb test, it indicates that there is a prob-
lem in the supplemental restraint system electrical
circuits. Such a problem may cause airbags not to
deploy when required, or to deploy when not
required.
Deployment of the supplemental restraints
depends upon the angle and severity of an impact.
Deployment is not based upon vehicle speed; rather,
deployment is based upon the rate of deceleration as
measured by the forces of gravity (G force) upon the
impact sensors. When an impact is severe enough,
the microprocessor in the ACM signals the inflator of
the appropriate airbag units to deploy their airbag
cushions. The outboard front seat belt tensioners are
provided with a deployment signal by the ACM in
conjunction with the driver and passenger front air-
bags. During a frontal vehicle impact, the knee block-
ers work in concert with properly fastened and
adjusted seat belts to restrain both the driver and
the front seat passenger in the proper position for an
airbag deployment. The knee blockers also absorb
and distribute the crash energy from the driver and
the front seat passenger to the structure of the
instrument panel. The seat belt tensioner removes
the slack from the outboard front seat belts to pro-
vide further assurance that the driver and front seat
passenger are properly positioned and restrained for
an airbag deployment.
Typically, the vehicle occupants recall more about
the events preceding and following a collision than
they do of an airbag deployment itself. This is
because the airbag deployment and deflation occur
very rapidly. In a typical 48 kilometer-per-hour (30
mile-per-hour) barrier impact, from the moment of
impact until the airbags are fully inflated takes
about 40 milliseconds. Within one to two seconds
from the moment of impact, the airbags are almost
entirely deflated. The times cited for these events are
approximations, which apply only to a barrier impact
at the given speed. Actual times will vary somewhat,
depending upon the vehicle speed, impact angle,
severity of the impact, and the type of collision.
When the ACM monitors a problem in any of the
supplemental restraint system circuits or compo-
nents, including the seat belt tensioners, it stores a
fault code or Diagnostic Trouble Code (DTC) in its
memory circuit and sends an electronic message to
the EMIC to turn on the airbag indicator. Propertesting of the supplemental restraint system compo-
nents, the Programmable Communications Interface
(PCI) data bus, the electronic message inputs to and
outputs from the EMIC or the ACM, as well as the
retrieval or erasure of a DTC from the ACM or EMIC
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of all of the factory-installed passive restraints.
WARNING
WARNINGS - RESTRAINT SYSTEM
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.
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.
DRRESTRAINTS 8O - 5
RESTRAINTS (Continued)

ment in the event of an accidental deployment. When
handling a non-deployed seat belt tensioner, take
proper care to keep fingers out from under the
retractor cover and away from the seat belt webbing
where it exits from the retractor cover. In addition,
the supplemental restraint system should be dis-
armed whenever any steering wheel, steering col-
umn, seat belt tensioner, airbag, impact sensor, or
instrument panel components require diagnosis or
service. Failure to observe this warning could result
in accidental airbag deployment and possible per-
sonal injury.
All damaged, faulty or non-deployed airbags and
seat belt tensioners which are replaced on vehicles
are to be handled and disposed of properly. If an air-
bag or seat belt tensioner unit is faulty or damaged
and non-deployed, refer to the Hazardous Substance
Control System for proper disposal. Dispose of all
non-deployed and deployed airbags and seat belt ten-
sioners in a manner consistent with state, provincial,
local and federal regulations.
SUPPLEMENTAL RESTRAINT STORAGE
Airbags and seat belt tensioners must be stored in
their original, special container until they are used
for service. Also, they must be stored in a clean, dry
environment; away from sources of extreme heat,
sparks, and high electrical energy. Always place or
store any airbag on a surface with its trim cover or
airbag cushion side facing up, to minimize movement
in case of an accidental deployment.
STANDARD PROCEDURE - SERVICE AFTER A
SUPPLEMENTAL RESTRAINT DEPLOYMENT
Any vehicle which is to be returned to use follow-
ing a supplemental restraint deployment, must have
the deployed restraints replaced. In addition, if the
driver airbag has been deployed, the clockspring
must be replaced. If the passenger airbag is
deployed, the passenger airbag door must be
replaced. The seat belt tensioners are deployed by
the same signal that deploys the driver and passen-
ger airbags and must also be replaced if either front
airbag has been deployed. If a side curtain airbag
has been deployed, the complete airbag unit, the
headliner, as well as the upper A, B, and C-pillar
trim must be replaced. These components are not
intended for reuse and will be damaged or weakened
as a result of a supplemental restraint deployment,
which may or may not be obvious during a visual
inspection.
It is also critical that the mounting surfaces and/or
mounting brackets for the Airbag Control Module
(ACM) and the side impact sensors be closely
inspected and restored to their original conditions fol-lowing any vehicle impact damage. Because the ACM
and each impact sensor are used by the supplemental
restraint system to monitor or confirm the direction
and severity of a vehicle impact, improper orientation
or insecure fastening of these components may cause
airbags not to deploy when required, or to deploy
when not required.
All other vehicle components should be closely
inspected following any supplemental restraint
deployment, but are to be replaced only as required
by the extent of the visible damage incurred.
AIRBAG SQUIB STATUS
Multistage airbags with multiple initiators (squibs)
must be checked to determine that all squibs were
used during the deployment event. The driver and
passenger airbags in this model are deployed by elec-
trical signals generated by the Airbag Control Mod-
ule (ACM) through the driver or passenger squib 1
and squib 2 circuits to the two initiators in the air-
bag inflators. Typically, both initiators are used and
all potentially hazardous chemicals are burned dur-
ing an airbag deployment event. However, it is possi-
ble for only one initiator to be used due to an airbag
system fault; therefore, it is always necessary to con-
firm that both initiators have been used in order to
avoid the improper handling or disposal of poten-
tially live pyrotechnic or hazardous materials. The
following procedure should be performed using a
DRBIIItscan tool to verify the status of both airbag
squibs before either deployed airbag is removed from
the vehicle for disposal.
CAUTION: Deployed front airbags having two initia-
tors (squibs) in the airbag inflator may or may not
have live pyrotechnic material within the inflator. Do
not dispose of these airbags unless you are sure of
complete deployment. Refer to the Hazardous Sub-
stance Control System for proper disposal proce-
dures. Dispose of all non-deployed and deployed
airbags in a manner consistent with state, provin-
cial, local, and federal regulations.
(1) Be certain that the DRBIIItscan tool contains
the latest version of the proper DRBIIItsoftware.
Connect the DRBIIItto the 16-way Data Link Con-
nector (DLC). The DLC is located on the driver side
lower edge of the instrument panel, outboard of the
steering column.
(2) Turn the ignition switch to the On position.
(3) Using the DRBIIIt, read and record the active
(current) Diagnostic Trouble Code (DTC) data.
Using the active DTC information, refer to theAir-
bag Squib Statustable to determine the status of
both driver and/or passenger airbag squibs.
DRRESTRAINTS 8O - 7
RESTRAINTS (Continued)

CAUTION: Deployed front airbags having two initia-
tors (squibs) in the airbag inflator may or may not
have live pyrotechnic material within the inflator. Do
not dispose of these airbags unless you are sure of
complete deployment. Refer to AIRBAG SQUIB STA-
TUS. All damaged, faulty, or non-deployed supple-
mental restraints which are replaced on vehicles
are to be handled and disposed of properly. If an
airbag or seat belt tensioner unit is faulty or dam-
aged and non-deployed, refer to the Hazardous
Substance Control System for proper disposal. Be
certain to dispose of all non-deployed and deployed
supplemental restraints in a manner consistent with
state, provincial, local and federal regulations.
(3) Next, remove the deployed supplemental
restraints from the vehicle. Refer to the appropriate
service removal procedures.
(4) You may need to vacuum the interior of the
vehicle a second time to recover all of the powder.
STANDARD PROCEDURE - VERIFICATION TEST
The following procedure should be performed using
a DRBIIItscan tool to verify proper supplemental
restraint system operation following the service or
replacement of any supplemental restraint system
component.
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 ORSERVICE. 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.
(1) During the following test, the battery negative
cable remains disconnected and isolated, as it was
during the supplemental restraint system component
removal and installation procedures.
(2) Be certain that the DRBIIItscan tool contains
the latest version of the proper DRBIIItsoftware.
Connect the DRBIIItto the 16-way Data Link Con-
nector (DLC). The DLC is located on the driver side
lower edge of the instrument panel, outboard of the
steering column (Fig. 5).
(3) Turn the ignition switch to the On position and
exit the vehicle with the DRBIIItscan tool.
(4) Check to be certain that nobody is in the vehi-
cle, then reconnect the battery negative cable.
(5) Using the DRBIIIt, read and record the active
(current) Diagnostic Trouble Code (DTC) data.
(6) Next, use the DRBIIItto read and record any
stored (historical) DTC data.
(7) If any DTC is found in Step 5 or Step 6, refer
to the appropriate diagnostic information.
(8) Use the DRBIIItto erase the stored DTC data.
If any problems remain, the stored DTC data will not
erase. Refer to the appropriate diagnostic informa-
tion to diagnose any stored DTC that will not erase.
Fig. 4 Vacuum Heater and A/C Outlets - Typical
Fig. 5 16-Way Data Link Connector - Typical
1 - 16-WAY DATA LINK CONNECTOR
2 - BOTTOM OF INSTRUMENT PANEL
DRRESTRAINTS 8O - 9
RESTRAINTS (Continued)

receptacles that face the instrument panel, while the
inner end of the tape terminates at the pigtail wires
and connector receptacles on the hub of the clock-
spring rotor that face the steering wheel.
Service replacement clocksprings are shipped pre-
centered and with a molded plastic locking pin that
snaps into a receptacle on the rotor and is engaged
between two tabs on the upper surface of the rotor
case. The locking pin secures the centered clock-
spring rotor to the clockspring case during shipment
and handling, but must be removed from the clock-
spring after it is installed on the steering column.
(Refer to 8 - ELECTRICAL/RESTRAINTS/CLOCK-
SPRING - STANDARD PROCEDURE - CLOCK-
SPRING CENTERING).
The clockspring cannot be repaired. If the clock-
spring is faulty, damaged, or if the driver airbag has
been deployed, the clockspring must be replaced.
OPERATION
The clockspring is a mechanical electrical circuit
component that is used to provide continuous electri-
cal continuity between the fixed instrument panel
wire harness and the electrical components mounted
on or in the rotating steering wheel. On this model
the rotating electrical components include the driver
airbag, the horn switch, the speed control switches,
and the remote radio switches, if the vehicle is so
equipped. The clockspring case is positioned and
secured to the multi-function switch mounting hous-
ing near the top of the steering column. The connec-
tor receptacles on the tail of the fixed clockspring
case connect the clockspring to the vehicle electrical
system through two take outs with connectors from
the instrument panel wire harness.The clockspring rotor is movable and is keyed by
an engagement dowel that is molded onto the rotor
hub between two fins that are cast into the lower
surface of the steering wheel armature. A yellow rub-
ber boot is installed over the engagement dowel to
eliminate contact noise between the dowel and the
steering wheel. The two lobes on the turn signal can-
cel cam on the lower surface of the clockspring rotor
hub contact a turn signal cancel actuator of the
multi-function switch to provide automatic turn sig-
nal cancellation.
Two short, yellow-sleeved pigtail wires on the
upper surface of the clockspring rotor connect the
clockspring to the driver airbag, while a steering
wheel wire harness connects the two connector recep-
tacles on the upper surface of the clockspring rotor to
the horn switch feed pigtail wire connector and, if
the vehicle is so equipped, to the optional speed con-
trol and remote radio switches on the steering wheel.
Like the clockspring in a timepiece, the clockspring
tape has travel limits and can be damaged by being
wound too tightly during full stop-to-stop steering
wheel rotation. To prevent this from occurring, the
clockspring is centered when it is installed on the
steering column. Centering the clockspring indexes
the clockspring tape to the movable steering compo-
nents so that the tape can operate within its
designed travel limits. However, if the clockspring is
removed from the steering column or if the steering
shaft is disconnected from the steering gear, the
clockspring spool can change position relative to the
movable steering components. The clockspring must
be re-centered following completion of this service or
the tape may be damaged.
Service replacement clocksprings are shipped pre-
centered and with a plastic locking pin installed.
This locking pin should not be removed until the
clockspring has been installed on the steering col-
umn. If the locking pin is removed before the clock-
spring is installed on a steering column, the
clockspring centering procedure must be performed.
(Refer to 8 - ELECTRICAL/RESTRAINTS/CLOCK-
SPRING - STANDARD PROCEDURE - CLOCK-
SPRING CENTERING).
STANDARD PROCEDURE - CLOCKSPRING
CENTERING
The clockspring is designed to wind and unwind
when the steering wheel is rotated, but is only
designed to rotate the same number of turns (about
five complete rotations) as the steering wheel can be
turned from stop to stop. Centering the clockspring
indexes the clockspring tape to other steering compo-
nents so that it can operate within its designed
travel limits. The rotor of a centered clockspring can
be rotated two and one-half turns in either direction
Fig. 18 Turn Signal Cancel Cam
1 - LOCKING PIN
2 - CLOCKSPRING CASE
3 - CANCEL CAM
4 - LOWER CONNECTOR RECEPTACLE (2)
DRRESTRAINTS 8O - 19
CLOCKSPRING (Continued)

from the centered position, without damaging the
clockspring tape.
However, if the clockspring is removed for service
or if the steering column is disconnected from the
steering gear, the clockspring tape can change posi-
tion relative to the other steering components. The
clockspring must then be re-centered following com-
pletion of such service or the clockspring tape may be
damaged. Service replacement clocksprings are
shipped pre-centered, with a molded plastic locking
pin installed (Fig. 19). This locking pin should not be
removed until the clockspring has been installed on
the steering column. If the locking pin is removed
before the clockspring is installed on a steering col-
umn, the clockspring centering procedure must be
performed.
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.
NOTE: Before starting this procedure, be certain to
turn the steering wheel until the front wheels are in
the straight-ahead position.
(1) Place the front wheels in the straight-ahead
position.
(2) Remove the clockspring from the steering col-
umn. (Refer to 8 - ELECTRICAL/RESTRAINTS/
CLOCKSPRING - REMOVAL).
(3) Rotate the clockspring rotor clockwise to the
end of its travel.Do not apply excessive torque.
(4) From the end of the clockwise travel, rotate the
rotor about two and one-half turns counterclockwise.
The engagement dowel and yellow rubber boot
should end up at the bottom, and the arrows on the
clockspring rotor and case should be in alignment.
(5) The clockspring is now centered. Secure the
clockspring rotor to the clockspring case to maintain
clockspring centering until it is reinstalled on the
steering column.
(6) The front wheels should still be in the straight-
ahead position. Reinstall the clockspring onto thesteering column. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/CLOCKSPRING - INSTALLATION).
REMOVAL
The clockspring cannot be repaired. It must be
replaced if faulty or damaged, or if the driver airbag
has been deployed.
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.
NOTE: Before starting this procedure, be certain to
turn the steering wheel until the front wheels are in
the straight-ahead position.
Fig. 19 Clockspring and Multi-Function Switch
1 - PIGTAIL WIRE (2)
2 - LOCATING TAB
3 - LOCKING PIN
4 - MOUNTING TAB (2)
5 - UPPER CONNECTOR RECEPTACLE (2)
6 - LABEL
7 - ENGAGEMENT DOWEL & BOOT
8 - CASE
9 - CENTERING ARROWS
10 - ROTOR
8O - 20 RESTRAINTSDR
CLOCKSPRING (Continued)