Fig DODGE RAM 1500 1998 2.G Workshop Manual

DIAGNOSIS AND TESTING - PASSENGER SEAT
SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power seat switch from the power
seat.
(3) Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart (Fig. 4). If OK, refer to
Power Seat Track Diagnosis and Testing in this
group. If not OK, replace the faulty power seat
switch.
PASSENGER SEAT SWITCH TEST TABLE
PASSENGER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL DOWN A-E, A-M, B-N, B-E
VERTICAL UP A-J, A-N, B-M, B-E
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT DOWN A-M, B-N
FRONT TILT UP A-N, B-M
REAR TILT DOWN A-E, B-J
REAR TILT UP A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMPAR UP (DEFLATE) O-P, Q-R
LUMBAR DOWN
(INFLATE)O-R, P-Q
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the seat cushion side shield from the
seat. Refer to the Body section of the service manual
for the procedure.
(3) Pull the switch bezel or side shield unit out
from the seat far enough to access the switch wire
harness connector. Gently pry the locking tabs of the
switch away from the wire harness connector and
carefully unplug the connector from the power seat
switch module.
(4) Remove the screws that secure the power seat
switch.
INSTALLATION
(1) Position the power seat switch on the seat
cushion bezel and install the screws that secure the
power seat switch to seat cushion side bezel.
(2) Connect the electrical connector.
(3) Install the seat cushion switch bezel on the
seat. Refer to the Body section of the service manual
for the procedure.
(4) If equipped, install the screw that secures the
recliner lever to the recliner mechanism release shaft
on the outboard side of the front seat.
(5) Connect the battery negative cable.
POWER SEAT TRACK
DESCRIPTION
The eight-way power seat option includes a power
seat track assembly located under each front seat
(Fig. 5). The power seat track assembly replaces the
standard manually operated seat tracks. The lower
half of the power seat track is secured at the front
with two bolts to the floor panel seat cross member,
and at the rear with two bolts to the floor panel.
Four nuts secure the bottom of the seat cushion
frame to the upper half of the power seat track unit.
The power seat track assembly cannot be repaired,
and is serviced only as a complete assembly. If any
component in this assembly is faulty or damaged, the
entire power seat track must be replaced.
OPERATION
The power seat track unit includes three reversible
electric motors that are secured to the upper half of
the track unit. Each motor moves the seat adjuster
through a combination of worm-drive gearboxes and
screw-type drive units.
The front and rear of the seat are operated by two
separate vertical adjustment motors. These motors
can be operated independently of each other, tilting
the entire seat assembly forward or rearward; or,
Fig. 4 Testing Passenger Power Seat Switch
8N - 16 POWER SEATSDR
PASSENGER SEAT SWITCH (Continued)

they can be operated in unison by selecting the
proper power seat switch functions, which will raise
or lower the entire seat assembly. The third motor is
the horizontal adjustment motor, which moves the
seat track in the forward and rearward directions.
DIAGNOSIS AND TESTING - POWER SEAT
TRACK
For complete power seat circuit descriptions and
diagrams, refer to Wiring Diagrams.
Operate the power seat switch to move all three
seat motors in each direction. The seat should move
in each of the selected directions. If the power seat
track fails to operate in only one direction, move the
seat track a short distance in the opposite direction
and test again to be certain that the track is not at
its travel limit. If the power seat track still fails to
operate in only one direction, refer to Diagnosis and
Testing of the Power Seat Switch in this section. If
the power seat track fails to operate in more than
one direction, proceed as follows:
(1) Check the power seat fuse in the power distri-
bution center. If OK, go to Step 2. If not OK, replace
the faulty fuse.
(2) Remove the power seat switch from the seat.
Check for battery voltage at the fused B(+) circuit
cavity of the power seat switch wire harness connec-
tor. If OK, go to Step 3. If not OK, repair the open
circuit to the power distribution center as required.(3) Check for continuity between the ground cir-
cuit cavity of the power seat switch wire harness con-
nector and a good ground. There should be
continuity. If OK, go to Step 4. If not OK, repair the
open circuit to ground as required.
(4) Test the power seat switch as described in this
group. If the switch tests OK, check the wire harness
between the power seat switch and the motor for
shorts or opens. If the circuits check OK, replace the
faulty power seat track (adjuster) assembly. If the
circuits are not OK, repair the wire harness as
required.
REMOVAL
(1) Remove the appropriate seat from the vehicle.
(Refer to 23 - BODY/SEATS/SEAT - REMOVAL).
(2) Remove the power seat switch from the seat.
Refer to the procedure in this section of the service
manual.
(3) Remove four seat track mounting nuts from
cushion pan.
(4) Disconnect the power seat electrical and
remove the seat track from the seat cushion.
(5) Remove the necessary components that must
be transferred to the replacement seat track (seat
belt buckles, wire harness, etc.).
INSTALLATION
(1) Install the necessary components that must be
transferred to the replacement seat track (seat belt
buckles, wire harness, etc.).
(2) Position the seat track and install the retaining
nuts on the seat cushion pan studs. Torque the bolts
to 25 N´m.
(3) Route and connect the power seat electrical on
the seat track and cushion pan.
(4) Install the power seat switch on the seat. Refer
to the procedure in this section of the service man-
ual.
(5) Install the seat in the vehicle (Refer to 23 -
BODY/SEATS/SEAT - INSTALLATION).
(6) Connect the negative battery cable.
LUMBAR CONTROL SWITCH
DESCRIPTION
The power lumbar seat option includes an electri-
cally operated lumbar support mechanism. A single
two-way momentary power lumbar switch is integral
with the power seat switches. The power lumbar
switch is secured to the back of the seat cushion side
shield with screws, and the switch paddle protrudes
through a hole to the outside of the shield. The
switch paddle is located in a shallow depression
molded into the outer surface of the seat cushion side
Fig. 5 DR Driver Power Seat Track
1 - POWER SEAT TRACK ASSEMBLY
2 - SEAT TRACK WIRE HARNESS
3 - SEAT BELT BUCKLE ASSEMBLIES
DRPOWER SEATS 8N - 17
POWER SEAT TRACK (Continued)

(5) Momentarily touch the Positive (+) jumper
probe to the other motor connector terminal.
When positive probe is connected the motor should
rotate in one direction to either move window up or
down. If window is all the way up or down the motor
will grunt and the inner door panel will flex when
actuated in that one direction.
(6) Reverse jumper probes at the motor connector
terminals and window should now move in opposite
direction. If window does not move or grunt, replace
the motor.
If window moved completely up or down, reverse
the jumper probes and cycle window to the opposite
position to verify full operation.
If motor grunts and does not move, verify that reg-
ulator is not binding.
WINDOW MOTOR
REMOVAL
The window motor is serviced with the window
regulator (Refer to 23 - BODY/DOOR - FRONT/WIN-
DOW REGULATOR - REMOVAL) or (Refer to 23 -
BODY/DOORS - REAR/WINDOW REGULATOR -
REMOVAL).
WINDOW SWITCH
DIAGNOSIS AND TESTING - WINDOW SWITCH
The Light-Emitting Diode (LED) illumination
lamps for all of the power window and lock switch
and bezel unit switch paddles receive battery current
through the power window circuit breaker in the
junction block. If all of the LEDs are inoperative in
both the power window and lock switch units and the
power windows are inoperative, (Refer to 8 - ELEC-
TRICAL/POWER WINDOWS - DIAGNOSIS AND
TESTING). If the power windows operate, but any or
all of the LEDs are inoperative, the power window
and lock switch units with the inoperative LED(s) is
faulty and must be replaced. For complete circuit dia-
grams, refer to the appropriate wiring information.
(1) Check the fuse in the Integrated Power Module
(IPM) and the circuit breaker located near the park
brake pedal. If OK, go to Step 2. If not OK, replace
the faulty fuse or circuit breaker.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fuse in the Inte-
grated Power Module (IPM). If OK, turn the ignition
switch to the Off position and go to Step 3. If not OK,
check circuit breaker and repair the circuit to the
ignition switch as required.
(3) Disconnect and isolate the battery negative
cable. Remove the power window switch unit fromthe door trim panel (passenger doors). The drivers
door switch is included with the Driver Door Module
(Refer to 8 - ELECTRICAL/POWER LOCKS/DOOR
MODULE - DIAGNOSIS AND TESTING) for service
procedures. Unplug the wire harness connector from
the switch unit.
(4) Test the power window switch continuity. See
the Power Window Switch Continuity charts to deter-
mine if the continuity is correct in the Off, Up and
Down switch positions (Fig. 1). If OK, (Refer to 8 -
ELECTRICAL/POWER WINDOWS - DIAGNOSIS
AND TESTING). If not OK, replace the faulty switch.
POWER WINDOW SWITCH CONTINUITY
CHART
SWITCH POSITION CONTINUITY BETWEEN
NEUTRAL PIN 2 AND 5, PIN 4 AND
1
UP (FRONT
PASSENGER)PIN 6 AND 5
UP (REAR
PASSENGER)PIN 6 AND 1
DOWN (FRONT
PASSENGER)PIN 6 AND 1
DOWN (REAR
PASSENGER)PIN 6 AND 5
REMOVAL
FRONT PASSENGER
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the door trim panel (Refer to 23 -
BODY/DOOR - FRONT/TRIM PANEL - REMOVAL).
(3) Remove the switch from the trim panel bezel.
Fig. 1 PASSENGER DOOR SWITCH
8N - 20 POWER WINDOWSDR
POWER WINDOWS (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

into the passenger airbag door on the instrument
panel above the glove box (Fig. 2). Vehicles with the
airbag system can also be identified by the airbag
indicator, which will illuminate in the instrument
cluster for about six seconds as a bulb test each time
the ignition switch is turned to the On position. A
pyrotechnic-type seat belt tensioner is integral to the
front outboard seat belt retractors mounted on each
lower B-pillar of all models equipped with dual front
airbags.
²Side Curtain Airbags- Optional side curtain
airbags are available for this model when it is also
equipped with dual front airbags. This airbag systemis a passive, inflatable, Supplemental Restraint Sys-
tem (SRS) and vehicles with this equipment can be
readily identified by a molded identification trim but-
ton with the ªSRS - AIRBAGº logo located on the
headliner above each B-pillar (Fig. 2).
The supplemental restraint system includes the
following major components, which are described in
further detail elsewhere in this service information:
²Airbag Control Module- The Airbag Control
Module (ACM) is also sometimes referred to as the
Occupant Restraint Controller (ORC). The ACM is
located on a mount on the floor panel transmission
tunnel, below the center of the instrument panel.
Fig. 1 Supplemental Restraint System
1 - AIRBAG CONTROL MODULE
2 - PASSENGER AIRBAG
3 - PASSENGER AIRBAG ON/OFF SWITCH (STD CAB ONLY)
4 - DRIVER AIRBAG5 - SIDE CURTAIN AIRBAG (2)
6 - SIDE IMPACT SENSOR (2 - W/SIDE CURTAIN AIRBAGS
ONLY)
7 - SEAT BELT TENSIONER (2)
DRRESTRAINTS 8O - 3
RESTRAINTS (Continued)

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 SQUIB STATUS
IF the Active DTC is: Conditions Squib Status
Driver or Passenger Squib 1
openANDthe stored DTC minutes for both Driver or
Passenger squibs are within 15 minutes of each
otherBoth Squib 1 and 2 were
used.
Driver or Passenger Squib 2
open
Driver or Passenger Squib 1
openANDthe stored DTC minutes for Driver or
Passenger Squib 2 open is GREATER than the
stored DTC minutes for Driver or Passenger
Squib 1 by 15 minutes or moreSquib 1 was used; Squib 2 is
live.
Driver or Passenger Squib 2
open
Driver or Passenger Squib 1
openANDthe stored DTC minutes for Driver or
Passenger Squib 1 open is GREATER than the
stored DTC minutes for Driver or Passenger
Squib 2 by 15 minutes or moreSquib 1 is live; Squib 2 was
used.
Driver or Passenger Squib 2
open
Driver or Passenger Squib 1
openANDDriver or Passenger Squib 2 open is NOT
an active codeSquib 1 was used; Squib 2 is
live.
Driver or Passenger Squib 2
openANDDriver or Passenger Squib 1 open is NOT
an active codeSquib 1 is live; Squib 2 was
used.
Ifnone of the Driver or Passenger Squib 1 or 2
open are active codes, the status of the airbag squibs
is unknown. In this case the airbag should be han-
dled and disposed of as if the squibs were both live.
CLEANUP PROCEDURE
Following a supplemental restraint deployment,
the vehicle interior will contain a powdery residue.
This residue consists primarily of harmless particu-
late by-products of the small pyrotechnic charge that
initiates the propellant used to deploy a supplemen-
tal restraint. However, this residue may also contain
traces of sodium hydroxide powder, a chemical
by-product of the propellant material that is used to
generate the inert gas that inflates the airbag. Since
sodium hydroxide powder can irritate the skin, eyes,
nose, or throat, be certain to wear safety glasses,
rubber gloves, and a long-sleeved shirt during
cleanup (Fig. 3).
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, IF YOU EXPERIENCE SKIN IRRITATION
DURING CLEANUP, RUN COOL WATER OVER THE
AFFECTED AREA. ALSO, IF YOU EXPERIENCE
IRRITATION OF THE NOSE OR THROAT, EXIT THE
VEHICLE FOR FRESH AIR UNTIL THE IRRITATION
CEASES. IF IRRITATION CONTINUES, SEE A PHYSI-
CIAN.
(1) Begin the cleanup by using a vacuum cleaner
to remove any residual powder from the vehicle inte-
rior. Clean from outside the vehicle and work your
way inside, so that you avoid kneeling or sitting on a
non-cleaned area.(2) Be certain to vacuum the heater and air condi-
tioning outlets as well (Fig. 4). Run the heater and
air conditioner blower on the lowest speed setting
and vacuum any powder expelled from the outlets.
Fig. 3 Wear Safety Glasses and Rubber Gloves -
Typical
8O - 8 RESTRAINTSDR
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)

If the stored DTC information is successfully erased,
go to Step 9.
(9) Turn the ignition switch to the Off position for
about fifteen seconds, and then back to the On posi-
tion. Observe the airbag indicator in the instrument
cluster. It should illuminate for six to eight seconds,
and then go out. This indicates that the supplemen-
tal restraint system is functioning normally and that
the repairs are complete. If the airbag indicator fails
to light, or lights and stays on, there is still an active
supplemental restraint system fault or malfunction.
Refer to the appropriate diagnostic information to
diagnose the problem.
ACM COVER
REMOVAL
The Airbag Control Module (ACM) cover is used
only on models with an automatic transmission. Mod-
els with a manual transmission require that the floor
console be removed to access the ACM for service.
(Refer to 23 - BODY/INTERIOR/FLOOR CONSOLE -
REMOVAL).
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.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Using a trim stick or another suitable wide
flat-bladed tool, gently pry each side of the ACM
cover away from the instrument panel at each side of
the center bracket on the floor panel transmission
tunnel far enough to disengage the two snap clip
retainers from the instrument panel receptacles (Fig.
6).
(3) Remove the ACM cover from the instrument
panel.
INSTALLATION
The Airbag Control Module (ACM) cover is used
only on models with an automatic transmission. Mod-
els with a manual transmission require that the floor
console be reinstalled following ACM service. (Refer
to 23 - BODY/INTERIOR/FLOOR CONSOLE -
INSTALLATION).
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.
(1) Position the ACM cover to the instrument
panel (Fig. 6).
(2) Align the snap clip retainer on each side of the
ACM cover with the instrument panel receptacle at
each side of the center bracket on the floor panel
transmission tunnel.
(3) Using hand pressure, press firmly and evenly
on the outside of the ACM cover over each snap clip
retainer location until each retainer is fully engaged
in its instrument panel receptacle.
(4) Reconnect the battery negative cable.
Fig. 6 ACM Cover Remove/Install
1 - INSTRUMENT PANEL RECEPTACLE (2)
2 - ACM COVER
8O - 10 RESTRAINTSDR
RESTRAINTS (Continued)

AIRBAG CONTROL MODULE
DESCRIPTION
The Airbag Control Module (ACM) is also some-
times referred to as the Occupant Restraint Control-
ler (ORC) (Fig. 7). The ACM is concealed below the
instrument panel center stack in the passenger com-
partment of the vehicle, where it is secured by three
screws to a stamped steel mounting bracket welded
onto the top of the floor panel transmission tunnel
just forward of the instrument panel center support
bracket. Concealed within a hollow in the center of
the die cast aluminum ACM housing is the electronic
circuitry of the ACM which includes a microproces-
sor, an electronic impact sensor, an electronic safing
sensor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ACM housing with four screws to enclose and protect
the internal electronic circuitry and components.
An arrow printed on the label on the top of the
ACM housing provides a visual verification of the
proper orientation of the unit, and should always be
pointed toward the front of the vehicle. The ACM
housing has integral mounting flanges on three cor-
ners. The mounting flange to the left of the connector
receptacle has an integral locating pin on its lower
surface. Both left side flanges have round mounting
holes, while the flange on the right side has a slotted
mounting hole. A molded plastic electrical connector
with two receptacles, one containing twenty-four ter-
minal pins and the other containing thirty-two termi-
nal pins, exits the rearward facing side of the ACM
housing. These terminal pins connect the ACM to the
vehicle electrical system through two dedicated takeouts and connectors of the instrument panel wire
harness.
The impact sensor and safing sensor internal to
the ACM are calibrated for the specific vehicle, and
are only serviced as a unit with the ACM. In addi-
tion, there are unique versions of the ACM for light
and heavy-duty models, and for vehicles with or
without the optional side curtain airbags. The ACM
cannot be repaired or adjusted and, if damaged or
faulty, it must be replaced.
OPERATION
The microprocessor in the Airbag Control Module
(ACM) contains the supplemental restraint system
logic circuits and controls all of the supplemental
restraint system components. The ACM uses
On-Board Diagnostics (OBD) and can communicate
with other electronic modules in the vehicle as well
as with the DRBIIItscan tool using the Programma-
ble Communications Interface (PCI) data bus net-
work. This method of communication is used for
control of the airbag indicator in the ElectroMechani-
cal Instrument Cluster (EMIC) and for supplemental
restraint system diagnosis and testing through the
16-way data link connector located on the driver side
lower edge of the instrument panel. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER/AIRBAG
INDICATOR - OPERATION).
The ACM microprocessor continuously monitors all
of the supplemental restraint system electrical cir-
cuits to determine the system readiness. If the ACM
detects a monitored system fault, it sets an active
and stored Diagnostic Trouble Code (DTC) and sends
electronic messages to the EMIC over the PCI data
bus to turn on the airbag indicator. An active fault
only remains for the duration of the fault, or in some
cases for the duration of the current ignition switch
cycle, while a stored fault causes a DTC to be stored
in memory by the ACM. For some DTCs, if a fault
does not recur for a number of ignition cycles, the
ACM will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
In standard cab models, the ACM also monitors a
resistor multiplexed input from the passenger airbag
on/off switch and provides a control output for the
Off indicator in the switch through a passenger air-
bag indicator driver circuit. If the passenger airbag
on/off switch is set to the Off position, the ACM turns
on the passenger airbag on/off switch Off indicator
and will internally disable the passenger airbag from
being deployed. The ACM also turns on the on/off
switch Off indicator for about seven seconds each
time the ignition switch is turned to the On position
as a bulb test. Following the bulb test, the ACM con-
trols the status of the Off indicator based upon the
Fig. 7 Airbag Control Module
1 - AIRBAG CONTROL MODULE
2 - ORIENTATION ARROW
3 - LABEL
4 - CONNECTOR RECEPTACLE (2)
DRRESTRAINTS 8O - 11