1998 DODGE RAM 1500 Electronic

(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)

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)

WARNING: TO AVOID PERSONAL INJURY OR
DEATH ON VEHICLES EQUIPPED WITH AIRBAGS,
BEFORE PERFORMING ANY WELDING OPERA-
TIONS DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE AND DISCONNECT
ALL WIRE HARNESS CONNECTORS FROM THE
AIRBAG CONTROL MODULE (ACM). FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND OTHER POSSIBLE DAMAGE TO THE SUPPLE-
MENTAL RESTRAINT SYSTEM CIRCUITS AND COM-
PONENTS.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, DO NOT ATTEMPT TO DISMANTLE AN AIR-
BAG UNIT OR TAMPER WITH ITS INFLATOR. DO
NOT PUNCTURE, INCINERATE, OR BRING INTO
CONTACT WITH ELECTRICITY. DO NOT STORE AT
TEMPERATURES EXCEEDING 93É C (200É F). AN
AIRBAG INFLATOR UNIT MAY CONTAIN SODIUM
AZIDE AND POTASSIUM NITRATE. THESE MATERI-
ALS ARE POISONOUS AND EXTREMELY FLAMMA-
BLE. CONTACT WITH ACID, WATER, OR HEAVY
METALS MAY PRODUCE HARMFUL AND IRRITAT-
ING GASES (SODIUM HYDROXIDE IS FORMED IN
THE PRESENCE OF MOISTURE) OR COMBUSTIBLE
COMPOUNDS. AN AIRBAG INFLATOR UNIT MAY
ALSO CONTAIN A GAS CANISTER PRESSURIZED
TO OVER 2500 PSI.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, WHEN HANDLING A SEAT BELT TEN-
SIONER RETRACTOR, PROPER CARE SHOULD BE
EXERCISED TO KEEP FINGERS OUT FROM UNDER
THE RETRACTOR COVER AND AWAY FROM THE
SEAT BELT WEBBING WHERE IT EXITS FROM THE
RETRACTOR COVER.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, REPLACE ALL RESTRAINT SYSTEM COM-
PONENTS ONLY WITH PARTS SPECIFIED IN THE
DAIMLERCHRYSLER MOPAR PARTS CATALOG.
SUBSTITUTE PARTS MAY APPEAR INTERCHANGE-
ABLE, BUT INTERNAL DIFFERENCES MAY RESULT
IN INFERIOR OCCUPANT PROTECTION.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, THE FASTENERS, SCREWS, AND BOLTS
ORIGINALLY USED FOR THE RESTRAINT SYSTEM
COMPONENTS MUST NEVER BE REPLACED WITH
ANY SUBSTITUTES. THESE FASTENERS HAVE
SPECIAL COATINGS AND ARE SPECIFICALLY
DESIGNED FOR THE RESTRAINT SYSTEM. ANY
TIME A NEW FASTENER IS NEEDED, REPLACE ITWITH THE CORRECT FASTENERS PROVIDED IN
THE SERVICE PACKAGE OR SPECIFIED IN THE
DAIMLERCHRYSLER MOPAR PARTS CATALOG.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, WHEN A STEERING COLUMN HAS AN AIR-
BAG UNIT ATTACHED, NEVER PLACE THE COL-
UMN ON THE FLOOR OR ANY OTHER SURFACE
WITH THE STEERING WHEEL OR AIRBAG UNIT
FACE DOWN.
DIAGNOSIS AND TESTING - SUPPLEMENTAL
RESTRAINT SYSTEM
Proper diagnosis and testing of the supplemental
restraint system components, the Programmable
Communications Interface (PCI) data bus, the data
bus electronic message inputs to and outputs from
the ElectroMechanical Instrument Cluster (EMIC),
the Airbag Control Module (ACM), as well as the
retrieval or erasure of a Diagnostic Trouble Code
(DTC) from the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
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.
STANDARD PROCEDURE
STANDARD PROCEDURE - HANDLING
NON-DEPLOYED SUPPLEMENTAL RESTRAINTS
At no time should any source of electricity be per-
mitted near the inflator on the back of a non-de-
ployed airbag or seat belt tensioner. When carrying a
non-deployed airbag, the trim cover or airbag cushion
side of the unit should be pointed away from the
body to minimize injury in the event of an accidental
deployment. If the airbag unit is placed on a bench or
any other surface, the trim cover or airbag cushion
side of the unit should be face up to minimize move-
8O - 6 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

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)

SIDE IMPACT SENSOR
DESCRIPTION
On vehicles equipped with the optional side curtain
airbags, two side impact sensors are used, one each
for the left and right sides of the vehicle (Fig. 54).
These sensors are mounted remotely from the bi-di-
rectional safing sensor that is internal to the Airbag
Control Module (ACM). The side impact sensors are
secured within the right and left B-pillars just above
the front seat belt retractors and behind the lower
B-pillar trim in the passenger compartment.
The impact sensor housing has an integral connec-
tor receptacle, an integral mounting stud, and an
integral locating tab. A cavity in the center of the
molded black plastic impact sensor housing contains
the electronic circuitry of the sensor, which includes
an electronic communication chip and an electronic
impact sensor. Potting material fills the cavity to seal
and protect the internal electronic circuitry and com-
ponents. The side impact sensors are each connected
to the vehicle electrical system through a dedicated
take out and connector of the body wire harness.
The side impact sensors cannot be repaired or
adjusted and, if damaged or faulty, they must be
replaced.
OPERATION
The side impact sensors are electronic accelerome-
ters that sense the rate of vehicle deceleration, which
provides verification of the direction and severity of
an impact. Each sensor also contains an electronic
communication chip that allows the unit to commu-
nicate the sensor status as well as sensor fault infor-
mation to the microprocessor in the Airbag Control
Module (ACM). The ACM microprocessor continu-
ously monitors all of the passive restraint system
electrical circuits to determine the system readiness.
If the ACM detects a monitored system fault, it sets
a Diagnostic Trouble Code (DTC) and controls the
airbag indicator operation accordingly.
The impact sensors each receive battery current
and ground through dedicated left and right sensor
plus and minus circuits from the ACM. The impact
sensors and the ACM communicate by modulating
the voltage in the sensor plus circuit. The hard wired
circuits between the side impact sensors and the
ACM may be diagnosed and tested using conven-
tional diagnostic tools and procedures. However, con-
ventional diagnostic methods will not prove
conclusive in the diagnosis of the ACM or the impact
sensors. The most reliable, efficient, and accurate
means to diagnose the impact sensors, the ACM, and
the electronic message communication between the
sensors and the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
REMOVAL - STANDARD CAB
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
Fig. 54 Side Impact Sensor
1 - SENSOR
2 - CONNECTOR RECEPTACLE
3 - STUD
DRRESTRAINTS 8O - 59

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - VACUUM
SUPPLY TEST.........................2
DIAGNOSIS AND TESTING - ROAD TEST....3
SPECIFICATIONS
TORQUE - SPEED CONTROL.............3
CABLE
DESCRIPTION..........................4
OPERATION............................4
REMOVAL.............................4
INSTALLATION..........................5
SERVO
DESCRIPTION..........................6OPERATION............................6
REMOVAL.............................6
INSTALLATION..........................6
SWITCH
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................8
INSTALLATION..........................8
VACUUM RESERVOIR
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - VACUUM
RESERVOIR..........................9
REMOVAL.............................9
INSTALLATION.........................10
SPEED CONTROL
DESCRIPTION
All 3.7L/4.7LGas Engines and/or Diesel With
Automatic Trans.
The speed control system is operated by the use of
a cable and a vacuum controlled servo. On all
engines except diesels, electronic control of the speed
control system is integrated into the Powertrain Con-
trol Module (PCM). If equipped with a diesel engine,
electronic control of the speed control system is inte-
grated into the Engine Control Module (ECM). The
controls consist of two steering wheel mounted
switches. The switches are labeled: ON/OFF, RES/
ACCEL, SET, COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
5.7L Gas
The speed control system is fully electronically con-
trolled by the Powertrain Control Module (PCM).A
cable and a vacuum controlled servo are not
used. This is a servo-less system.The controls
consist of two steering wheel mounted switches. The
switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
DRSPEED CONTROL 8P - 1