Test mode DODGE RAM 1500 1998 2.G Repair Manual

(1) Enter the vehicle and close all doors.
(2) Fasten the seat belt (this will cancel the seat
belt chime).
(3) Turn the ignition to the ON position.
(4) Press and hold the LOCK button for 4 seconds.
Within 6 seconds with the LOCK button still
depressed, press the PANIC button. When a single
chime is heard, release both buttons.
(5) Turn the ignition OFF.
(6) Turn the ignition ON or wait 60 seconds.
(7) Test the optical chirp feature by pressing the
LOCK button.
If a chime is not heard, program mode was can-
celed before the feature could be disabled. If neces-
sary, repeat the procedure.
To ENABLE the optical chirp feature, repeat the
above procedure.
UNLOCK SEQUENCE
The unlock sequence can be toggled using a DRB
IIItor by using the Remote Keyless Entry (RKE)
transmitter that is already programmed to the vehi-
cle.
To toggle between Driver door first and Unlock all
doors function:
(1) Enter the vehicle and close all doors.
(2) Fasten the seat belt (this will cancel the seat
belt chime).
(3) Turn the ignition to the ON position.
(4) Press and hold the UNLOCK button for 4 sec-
onds. Within 6 seconds with the UNLOCK button
still depressed, press the LOCK button. When a sin-
gle chime is heard, release both buttons.
(5) Turn the ignition OFF.
(6) Turn the ignition ON or wait 60 seconds.
If a chime is not heard, program mode was can-
celed before the feature could be disabled. If neces-
sary, repeat the procedure.
To toggle this feature, repeat the above procedure.
STANDARD PROCEDURE - RKE TRANSMITTER
PROGRAMING
New Remote Keyless Entry (RKE) transmitters can
be programed using the DRB IIItscan tool and the
proper Diagnostic Procedures manual. The DRB IIIt
scan tool can provide confirmation that the PCI data
bus is functional, and that all of the electronic mod-
ules are sending and receiving the proper messages
on the PCI data bus.The following procedure can be used as long as one
programmed transmitter is available:
NOTE: When entering program mode using that
programmed fob, ALL currently programmed fobs
will be erased and they will have to be repro-
grammed for the vehicle. If program mode is
entered and no action is performed, the previously
programmed fobs will continue to function.
(1) Enter the vehicle and close all doors.
(2) Fasten the seat belt (this will cancel the seat
belt chime). Turn the ignition to the RUN position.
(3) Press and hold the UNLOCK button on a pro-
grammed transmitter for 4 to 10 seconds. Within the
4 to 10 seconds with the UNLOCK button still
depressed, press the PANIC button for one second.
When a single chime is heard, release both button-
s.The chime indicates the system is in program
mode.
(4) Press and release both the LOCK and
UNLOCK buttons simultaneously on a fob to be pro-
grammed. A single chime will be heard, this indicates
the fob has been recognized.
(5) Press and release any button on the same fob.
A single chime will be heard, this indicates the fob
has been programmed.
(6) Repeat steps 4 and 5 for up to a total of 4 fobs.
(7) Turn the ignition OFF.
(8) Turn the ignition ON or wait 60 seconds.
The vehicle will remain in program mode for up to
60 seconds from when the original chime (step 3) was
heard. After 60 seconds, all programmed transmitters
will function normally.
SPECIFICATIONS - REMOTE KEYLESS ENTRY
TRANSMITTER
RANGE
Normal operation range is up to a distance of 3 to
7 meters (10 to 23 ft.) of the vehicle. Range may be
better or worse depending on the environment
around the vehicle.
DRPOWER LOCKS 8N - 9
REMOTE KEYLESS ENTRY TRANSMITTER (Continued)

POWER SEATS
TABLE OF CONTENTS
page page
POWER SEATS
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM............................13
DRIVER SEAT SWITCH
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - DRIVER SEAT
SWITCH............................14
REMOVAL.............................15
INSTALLATION.........................15
PASSENGER SEAT SWITCH
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - PASSENGER
SEAT SWITCH........................16REMOVAL.............................16
INSTALLATION.........................16
POWER SEAT TRACK
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - POWER SEAT
TRACK.............................17
REMOVAL.............................17
INSTALLATION.........................17
LUMBAR CONTROL SWITCH
DESCRIPTION.........................17
OPERATION...........................18
REMOVAL.............................18
LUMBAR MOTOR
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - LUMBAR MOTOR . 18
POWER SEATS
DESCRIPTION
The power seat system option allows the driver or
passenger to electrically adjust the seat position for
optimum control and comfort using the power seat
switches located on the outboard seat cushion side
shield. The power seat system allows the seating
position to be adjusted forward, rearward, front up,
front down, rear up, or rear down. The power seat
system receives battery current through a fuse in the
Integrated Power Module, regardless of the ignition
switch position. The power seat system includes the
following components:
²Driver Power Seat Switch
²Passenger Power Seat Switch
²Driver Power Seat Track
²Passenger Power Seat Track
²Power Lumbar Adjuster(s)
Some models equipped with the power seat option
also feature a power operated lumbar support in the
seat back. The power lumbar support allows the user
to inflate or deflate a bladder located in the lower
seat back to achieve optimum comfort and support in
the lower lumbar region of the spinal column. The
power lumbar support shares the battery feed circuit
of the power seat system.
Following are general descriptions of the major
components in the power seat system. Refer to
Heated Seat Systemfor information on the individ-ually controlled heated front seats. Refer to the own-
er's manual in the vehicle glove box for more
information on the features, use and operation of the
power seat system.
OPERATION
The power seat system allows the driver and/or
front passenger seating positions to be adjusted elec-
trically and independently using the separate power
seat switches found on the outboard seat cushion
side shield of each front seat. See the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
Before any testing of the power seat system is
attempted, the battery should be fully-charged and
all wire harness connections and pins checked to
ensure proper continuity and grounds. For circuit
descriptions and diagrams, refer to Wiring Diagrams.
With the dome lamp on, apply the power seat
switch in the direction of the failure. If the dome
lamp dims, the seat may be jamming. Check under
and behind the seat for binding or obstructions. If
the dome lamp does not dim, proceed with testing of
the individual components and circuits.
DRPOWER SEATS 8N - 13

DRIVER SEAT SWITCH
DESCRIPTION
The power seat on this model can be adjusted in
eight different directions, up, down, front up, front
down, rear up, rear down, rearward and forward.
The power seat switch (Fig. 1) on this model has an
additional switch knob for adjusting the power lum-
bar support. The power seat switch is located on the
outboard side of the seat cushion on the seat cushion
side shield. Refer to the owner's manual in the vehi-
cle glove box for more information on the power seat
switch functions and the seat adjusting procedures.
The individual switches in the power seat switch
assembly cannot be repaired. If one switch is dam-
aged or faulty, the entire power seat switch assembly
must be replaced.
OPERATION
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch ismoved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
DIAGNOSIS AND TESTING - DRIVER 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. 2). If OK, refer to
Power Seat Track Diagnosis and Testing in this
group. If not OK, replace the faulty power seat
switch.
DRIVER POWER SEAT SWITCH TEST TABLE
DRIVER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL UP A-E, A-M, B-N, B-J
VERTICAL DOWN A-J, A-N, B-M, B-E
Fig. 1 DR Power Seat Switch
1 - POWER SEAT SWITCH ASSEMBLY
2 - FRONT SEAT CUSHION ADJUSTMENT BUTTON
3 - COMPLETE SEAT ADJUSTMENT BUTTON
4 - REAR SEAT CUSHION ADJUSTMENT BUTTON
5 - LUMBAR ADJUSTMENT BUTTON
Fig. 2 Testing Driver Power Seat Switch
8N - 14 POWER SEATSDR

DRIVER POWER SEAT SWITCH TEST TABLE
DRIVER SWITCH
POSITIONCONTINUITY BETWEEN
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT UP A-M, B-N
FRONT TILT DOWN A-N, B-M
REAR TILT UP A-E, B-J
REAR TILT DOWN A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMPAR UP (INFLATE) O-P, Q-R
LUMBAR DOWN
(DEFLATE)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 side shield and install the screws that secure
the power seat switch to seat cushion side shield.
(2) Connect the electrical connector.
(3) Install the seat cushion side shield 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.
PASSENGER SEAT SWITCH
DESCRIPTION
The power seat on this model can be adjusted in
eight different directions, up, down, front up, front
down, rear up, rear down, rearward and forward.
The power seat switch (Fig. 3) on this model has an
additional switch knob for adjusting the power lum-bar support. The power seat switch is located on the
outboard side of the seat cushion on the seat cushion
side shield. Refer to the owner's manual in the vehi-
cle glove box for more information on the power seat
switch functions and the seat adjusting procedures.
The individual switches in the power seat switch
assembly cannot be repaired. If one switch is dam-
aged or faulty, the entire power seat switch assembly
must be replaced.
OPERATION
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
Fig. 3 DR Power Seat Switch
1 - POWER SEAT SWITCH ASSEMBLY
2 - FRONT SEAT CUSHION ADJUSTMENT BUTTON
3 - COMPLETE SEAT ADJUSTMENT BUTTON
4 - REAR SEAT CUSHION ADJUSTMENT BUTTON
5 - LUMBAR ADJUSTMENT BUTTON
DRPOWER SEATS 8N - 15
DRIVER SEAT SWITCH (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)

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)

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

resistance of the input from the on/off switch. The
ACM will also set and/or store a DTC for faults it
detects in the passenger airbag on/off switch circuits,
and will turn on the airbag indicator in the EMIC if
a fault has been detected.
The ACM receives battery current through two cir-
cuits; a fused ignition switch output (run) circuit
through a fuse in the Integrated Power Module
(IPM), and a fused ignition switch output (run-start)
circuit through a second fuse in the IPM. The ACM
receives ground through a ground circuit and take
out of the instrument panel wire harness. This take
out has a single eyelet terminal connector that is
secured by a ground screw to the instrument panel
support structure. These connections allow the ACM
to be operational whenever the ignition switch is in
the Start or On positions.
The ACM also contains an energy-storage capaci-
tor. When the ignition switch is in the Start or On
positions, this capacitor is continually being charged
with enough electrical energy to deploy the supple-
mental restraint components for up to one second fol-
lowing a battery disconnect or failure. The purpose of
the capacitor is to provide backup supplemental
restraint system protection in case there is a loss of
battery current supply to the ACM during an impact.
Two sensors are contained within the ACM, an
electronic impact sensor and a safing sensor. The
electronic impact sensors are accelerometers that
sense the rate of vehicle deceleration, which provide
verification of the direction and severity of an
impact. On models equipped with optional side cur-
tain airbags, the ACM also monitors inputs from two
remote side impact sensors located within both the
left and right B-pillars to control deployment of the
side curtain airbag units.
The safing sensor is an electronic accelerometer
sensor within the ACM that provides an additional
logic input to the ACM microprocessor. The safing
sensor is used to verify the need for a supplemental
restraint deployment by detecting impact energy of a
lesser magnitude than that of the primary electronic
impact sensors, and must exceed a safing threshold
in order for the airbags to deploy. Vehicles equipped
with optional side curtain airbags feature a second
safing sensor within the ACM to provide confirma-
tion to the ACM microprocessor of side impact forces.
This second safing sensor is a bi-directional unit that
detects impact forces from either side of the vehicle.
Pre-programmed decision algorithms in the ACM
microprocessor determine when the deceleration rate
as signaled by the impact sensors and the safing sen-
sors indicate an impact that is severe enough to
require supplemental restraint system protection
and, based upon the severity of the monitored impact
and the status of the passenger airbag on/off switchinput, determines the level of front airbag deploy-
ment force required for each front seating position.
When the programmed conditions are met, the ACM
sends the proper electrical signals to deploy the dual
multistage front airbags at the programmed force
levels, the front seat belt tensioners and, if the vehi-
cle is so equipped, either side curtain airbag unit.
The hard wired inputs and outputs for the ACM
may be diagnosed and tested using conventional
diagnostic tools and procedures. However, conven-
tional diagnostic methods will not prove conclusive in
the diagnosis of the ACM, the PCI data bus network,
or the electronic message inputs to and outputs from
the ACM. The most reliable, efficient, and accurate
means to diagnose the ACM, the PCI data bus net-
work, and the electronic message inputs to and out-
puts from the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
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.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, NEVER STRIKE OR DROP THE AIRBAG
CONTROL MODULE, AS IT CAN DAMAGE THE
IMPACT SENSOR OR AFFECT ITS CALIBRATION.
THE AIRBAG CONTROL MODULE CONTAINS THE
IMPACT SENSOR, WHICH ENABLES THE SYSTEM
TO DEPLOY THE SUPPLEMENTAL RESTRAINTS. IF
AN AIRBAG CONTROL MODULE 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.
8O - 12 RESTRAINTSDR
AIRBAG CONTROL MODULE (Continued)

panel transmission tunnel. Tighten the screws to 12
N´m (9 ft. lbs.).
(4) From the left side of the floor panel transmis-
sion tunnel, reach behind the module to access and
tighten the screw that secures the right side of the
ACM to the bracket on the floor panel transmission
tunnel. Tighten the screw to 12 N´m (9 ft. lbs.).
(5) Reach through the rearward facing opening
below the instrument panel center stack support
bracket on the top of the floor panel transmission
tunnel to access and reconnect the two instrument
panel wire harness connectors for the ACM to the
ACM connector receptacle located on the rearward
facing side of the module. Be certain that the latches
on the connectors are each fully engaged.
(6) On models with an automatic transmission,
reinstall the ACM cover onto the instrument panel.
(Refer to 8 - ELECTRICAL/RESTRAINTS/ACM
COVER - INSTALLATION).
(7) On models with a manual transmission, rein-
stall the floor console onto the top of the floor panel
transmission tunnel. (Refer to 23 - BODY/INTERI-
OR/FLOOR CONSOLE - INSTALLATION).
(8) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
AUTOMATIC LOCKING
RETRACTOR
DESCRIPTION
The seat belt retractors used in all seating posi-
tions include an inertia-type, emergency locking
mechanism as standard equipment (Fig. 9). However,
the retractor locking mechanism for the passenger
side front seating position is mechanically switchable
from an emergency locking retractor to an automatic
locking retractor. The primary function of this fea-
ture is to securely accommodate a child seat in the
passenger side front seating position of the vehicle
without the need for a self-cinching seat belt tip half
latch plate unit or another supplemental device that
would be required to prevent the seat belt webbing
from unwinding freely from the retractor spool of an
inertia-type emergency locking retractor mechanism.
The automatic locking mechanism is integral to the
passenger side front seat belt and retractor unit and
is concealed beneath a molded plastic cover located
on the same side of the retractor spool as the seat
belt tensioner housing. The retractor is secured to
the inner B-pillar on the right side of the vehicle and
is concealed beneath the molded plastic inner B-pil-lar trim. The automatic locking mechanism cannot be
adjusted or repaired and, if faulty or damaged, the
entire passenger side front seat belt and retractor
unit must be replaced.
OPERATION
The automatic locking mode of the retractor is
engaged and the retractor is switched from operating
as a standard inertia-type emergency locking retrac-
tor by first buckling the combination lap and shoul-
der belt buckle. Then grasp the shoulder belt and
pull all of the webbing out of the retractor. Once all
of the belt webbing is extracted from the spool, the
retractor will automatically become engaged in the
pre-locked automatic locking mode and will make an
audible clicking or ratcheting sound as the shoulder
belt is allowed to retract to confirm that the auto-
matic locking mode is now engaged. Once the auto-
matic locking mode is engaged, the retractor will
remain locked and the belt will remain tight around
whatever it is restraining.
The retractor is returned to standard emergency
locking mode by unbuckling the combination lap and
shoulder belt buckle and allowing the belt webbing to
be almost fully retracted onto the retractor spool. The
emergency locking mode is confirmed by the absence
of the audible clicking or ratcheting sound as the belt
webbing retracts. This mode will allow the belt to
unwind from and wind onto the retractor spool freely
unless and until a predetermined inertia load is
sensed, or until the retractor is again switched to the
automatic locking mode.
Fig. 9 Automatic Locking Retractor
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
7 - RETRACTOR LOCKING MECHANISM COVER
8O - 14 RESTRAINTSDR
AIRBAG CONTROL MODULE (Continued)