2002 JEEP LIBERTY Electronic control modules

The ACM housing also has an integral ground lug
with a tapped hole that protrudes from the lower left
rear corner of the unit. This lug provides a case
ground to the ACM when a ground screw is installed
through the left side of the mounting bracket. Two
molded plastic electrical connector receptacles exit
the right side of the ACM housing. The smaller of the
two receptacles contains twelve terminal pins, while
the larger one contains twenty-three. These terminal
pins connect the ACM to the vehicle electrical system
through two dedicated take outs and connectors of
the instrument panel wire harness.
A molded rubber protective cover is installed
loosely over the ACM to protect the unit from con-
densation or coolant leaking from a damaged or
faulty heater-air conditioner unit housing. An inte-
gral flange on the left side of the cover is secured to
the floor panel transmission tunnel with a short
piece of double-faced tape as an assembly aid during
the manufacturing process, but this tape does not
require replacement following service removal.
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. The ACM
cannot be repaired or adjusted and, if damaged or
faulty, it must be replaced. The ACM cover is avail-
able for separate service replacement.
OPERATION
The microprocessor in the Airbag Control Module
(ACM) contains the front supplemental restraint sys-
tem logic circuits and controls all of the front supple-
mental 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 front supplemental restraint system electrical
circuits 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 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 afault 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
forever.
On models equipped with optional side curtain air-
bags, the ACM communicates with both the left and
right Side Impact Airbag Control Modules (SIACM)
over the PCI data bus. The SIACM notifies the ACM
when it has detected a monitored system fault and
stored a DTC in memory for its respective side cur-
tain airbag system, and the ACM sets a DTC and
controls the airbag indicator operation accordingly.
The ACM also monitors a Hall effect-type seat belt
switch located in the buckle of each front seat belt to
determine whether the seatbelts are buckled, and
provides an input to the EMIC over the PCI data bus
to control the seatbelt indicator operation based upon
the status of the driver side front seat belt switch.
The ACM receives battery current through two cir-
cuits; a fused ignition switch output (run) circuit
through a fuse in the Junction Block (JB), and a
fused ignition switch output (run-start) circuit
through a second fuse in the JB. The ACM has a case
ground through a lug on the bottom of the ACM
housing that is secured with a ground screw to the
left side of the ACM mounting bracket. The ACM
also receives a power ground through a ground cir-
cuit and take out of the instrument panel wire har-
ness. This take out has a single eyelet terminal
connector that is secured by a second ground screw
to the left side of the ACM mounting bracket. These
connections allow the ACM to be operational when-
ever the ignition switch is in the Start or On posi-
tions. The ACM also contains an energy-storage
capacitor. When the ignition switch is in the Start or
On positions, this capacitor is continually being
charged with enough electrical energy to deploy the
airbags for up to one second following a battery dis-
connect or failure. The purpose of the capacitor is to
provide backup supplemental restraint system pro-
tection in case there is a loss of battery current sup-
ply to the ACM during an impact.
Two sensors are contained within the ACM, an
electronic impact sensor and a safing sensor. The
ACM also monitors inputs from two remote front
impact sensors located on the back of the right and
left vertical members of the radiator support near
the front of the vehicle. The electronic impact sensors
are accelerometers that sense the rate of vehicle
deceleration, which provides verification of the direc-
tion and severity of an impact. The safing sensor is
an electromechanical sensor within the ACM that
provides an additional logic input to the ACM micro-
processor. The safing sensor is a normally open
switch that is used to verify the need for an airbag
deployment by detecting impact energy of a lesser
8O - 10 RESTRAINTSKJ
AIRBAG CONTROL MODULE (Continued)

(10) Reinstall the headliner into the vehicle. (Refer
to 23 - BODY/INTERIOR/HEADLINER - INSTALLA-
TION).
(11) Reinstall the lower trim onto the inside of the
B-pillar. (Refer to 23 - BODY/INTERIOR/B-PILLAR
LOWER TRIM - INSTALLATION).
(12) Do not reconnect the battery negative cable at
this time. The airbag system verification test proce-
dure should be performed following service of any
supplemental restraint system component. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - VERIFICATION TEST).
SIDE IMPACT AIRBAG
CONTROL MODULE
DESCRIPTION
On vehicles equipped with the optional side curtain
airbags, a Side Impact Airbag Control Module
(SIACM) and its mounting bracket are secured with
four screws to the sill panel at the base of each B-pil-
lar behind the lower B-pillar trim (Fig. 43). Con-
cealed within a hollow in the center of the die cast
aluminum SIACM housing is the electronic circuitry
of the SIACM which includes a microprocessor and
an electronic impact sensor. The SIACM housing is
secured to a stamped steel mounting bracket, which
is unique for the right or left side application of this
component. The SIACM should never be removed
from its mounting bracket. The housing also receives
a case ground through this mounting bracket when it
is secured to the vehicle. A molded plastic electrical
connector receptacle that exits the top of the SIACMhousing connects the unit to the vehicle electrical
system through a dedicated take out and connector of
the body wire harness. Both the SIACM housing and
its electrical connection are sealed to protect the
internal electronic circuitry and components against
moisture intrusion.
The impact sensor internal to the SIACM is cali-
brated for the specific vehicle, and is only serviced as
a unit with the SIACM. The SIACM cannot be
repaired or adjusted and, if damaged or faulty, it
must be replaced.
OPERATION
The microprocessor in the Side Impact Airbag Con-
trol Module (SIACM) contains the side curtain airbag
system logic circuits and controls all of the features
of only the side curtain airbag mounted on the same
side of the vehicle as the SIACM. The SIACM 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 by the
SIACM to communicate with the Airbag Control
Module (ACM) and for supplemental restraints sys-
tem diagnosis and testing through the 16-way data
link connector located on the driver side lower edge
of the instrument panel. The ACM communicates
with both the left and right SIACM over the PCI
data bus.
The SIACM microprocessor continuously monitors
all of the side curtain airbag electrical circuits to
determine the system readiness. If the SIACM
detects a monitored system fault, it sets an active
and stored Diagnostic Trouble Code (DTC) and sends
electronic messages to the ACM over the PCI data
bus. The ACM will respond by sending an electronic
message to the EMIC to turn on the airbag indicator,
and by storing a DTC that will indicate whether the
left or the right SIACM has stored the DTC that ini-
tiated the airbag indicator illumination. An active
fault only remains for the current ignition switch
cycle, while a stored fault causes a DTC to be stored
in memory by the SIACM. For some DTCs, if a fault
does not recur for a number of ignition cycles, the
SIACM will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
The SIACM receives battery current on a fused
ignition switch output (run-start) circuit through a
fuse in the Junction Block (JB). The SIACM has a
case ground through its mounting bracket and also
receives a power ground through a ground circuit
and take out of the body wire harness. This take out
has a single eyelet terminal connector that is secured
by a ground screw to the front seat front crossmem-
Fig. 43 Side Impact Airbag Control Module
1 - BRACKET (RIGHT SHOWN)
2 - CONNECTOR RECEPTACLE
3 - SIACM
KJRESTRAINTS 8O - 43
SIDE CURTAIN AIRBAG (Continued)

in vehicles manufactured for sale in certain markets
where it is required equipment. The ROW premium
version of the VTA provides the same perimeter pro-
tection features as the base version, but adds interior
vehicle intrusion protection. The ROW premium VTA
also replaces the pulsing horn feature of the base
version with an alarm siren as the audible deterrent,
while retaining the flashing exterior lamps visual
deterrent.The VTA includes the following major components,
which are described in further detail elsewhere in
this service information:
²Body Control Module- The Body Control
Module (BCM) is located on the Junction Block (JB)
under the driver side outboard end of the instrument
panel. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/BODY CONTROL MODULE
- DESCRIPTION).
Fig. 1 Vehicle Theft Security System
1 - SIREN MODULE
2 - BODY CONTROL MODULE
3 - SENTRY KEY IMMOBILIZER MODULE4 - DOOR CYLINDER LOCK SWITCH (2)
5 - INTRUSION TRANSCEIVER MODULE
8Q - 2 VEHICLE THEFT SECURITYKJ
VEHICLE THEFT SECURITY (Continued)

²Combination Flasher- An electronic combina-
tion flasher is integral to the hazard switch located
in the center of the instrument panel above the
radio. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/COMBINATION FLASHER -
DESCRIPTION).
²Door Ajar Switch- A door ajar switch is inte-
gral to the latch of each door in the vehicle. (Refer to
8 - ELECTRICAL/LAMPS/LIGHTING - INTERIOR/
DOOR AJAR SWITCH - DESCRIPTION).
²Door Cylinder Lock Switch- For North
American vehicles only, a door cylinder lock switch is
located on the back of the lock cylinder of each front
door. (Refer to 8 - ELECTRICAL/VEHICLE THEFT
SECURITY/DOOR CYLINDER LOCK SWITCH -
DESCRIPTION).
²Flip-Up Glass Ajar Switch- A flip-up glass
ajar switch is integral to the rear flip-up glass latch,
located on the top of the tailgate near the center.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
INTERIOR/FLIP-UP GLASS AJAR SWITCH -
DESCRIPTION).
²Hood Ajar Switch- A hood ajar switch is
located beneath the hood panel on the right inner
fender side shield of vehicles built for sale in certain
markets where it is required equipment. (Refer to 8 -
ELECTRICAL/VEHICLE THEFT SECURITY/HOOD
AJAR SWITCH - DESCRIPTION).
²Horn Relay- A horn relay is located on the
Junction Block (JB) under the driver side outboard
end of the instrument panel. (Refer to 8 - ELECTRI-
CAL/HORN/HORN RELAY - DESCRIPTION).
²Intrusion Transceiver Module- An Intrusion
Transceiver Module (ITM) is located near the center
of the headliner in the passenger compartment of
vehicles built for sale in certain markets where it is
required equipment. (Refer to 8 - ELECTRICAL/VE-
HICLE THEFT SECURITY/UK SECURITY SYSTEM
MODULE - DESCRIPTION).
²Security Indicator- A security indicator is
located in the ElectroMechanical Instrument Cluster
(EMIC) on the instrument panel in front of the driver
side front seat. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER/SECURITY INDICATOR -
DESCRIPTION).
²Siren- An alarm siren is located on the front
extension of the right front wheel house panel in the
engine compartment of vehicles built for sale in cer-
tain markets where it is required equipment. (Refer
to 8 - ELECTRICAL/VEHICLE THEFT SECURITY/
SIREN - DESCRIPTION).
²Tailgate Ajar Switch- A tailgate ajar switch is
integral to the latch for the tailgate in the vehicle.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
INTERIOR/TAILGATE AJAR SWITCH - DESCRIP-
TION).SENTRY KEY IMMOBILIZER SYSTEM The Sen-
try Key Immobilizer System (SKIS) is available as a
factory-installed option on this model. Vehicles
equipped with the Vehicle Theft Alarm (VTA) are also
equipped with SKIS. The SKIS provides passive vehi-
cle protection by preventing the engine from operat-
ing unless a valid electronically encoded key is
detected in the ignition lock cylinder. The SKIS
includes the following major components, which are
described in further detail elsewhere in this service
information:
²Powertrain Control Module- The Powertrain
Control Module (PCM) is located on the left inner
fender shield in the engine compartment near the
dash panel. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/POWERTRAIN
CONTROL MODULE - DESCRIPTION).
²Sentry Key Immobilizer Module- The Sentry
Key Immobilizer Module (SKIM) is located beneath
the steering column shrouds on the right side of the
steering column near the ignition lock cylinder hous-
ing. (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/SENTRY KEY IMMOBILIZER
MODULE - DESCRIPTION).
²Sentry Key Transponder- The Sentry Key
transponder is molded into the head of the ignition
key, and concealed by a gray molded rubber cap.
(Refer to 8 - ELECTRICAL/VEHICLE THEFT SECU-
RITY/TRANSPONDER KEY - DESCRIPTION).
²SKIS Indicator- The SKIS indicator is located
in the ElectroMechanical Instrument Cluster (EMIC)
on the instrument panel in front of the driver side
front seat. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER/SPEED CONTROL INDICATOR -
DESCRIPTION).
OPERATION
The Vehicle Theft Security System (VTSS) is
divided into two basic subsystems: Vehicle Theft
Alarm (VTA) and Sentry Key Immobilizer System
(SKIS). Following are paragraphs that briefly
describe the operation of each of these two sub-
systems.
VEHICLE THEFT ALARM The Body Control Mod-
ule (BCM) is used on this model to control and inte-
grate many of the electronic functions and features
included in the Vehicle Theft Alarm (VTA). The BCM
receives hard wired inputs indicating the status of
the door ajar switches, the door cylinder lock
switches, the ignition switch, the tailgate ajar switch,
the tailgate cylinder lock switch, the flip-up glass
ajar switch, the power lock switches and, in vehicles
built for certain markets where it is required, the
hood ajar switch. The programming in the BCM
allows it to process the information from all of these
inputs and send control outputs to energize or de-en-
KJVEHICLE THEFT SECURITY 8Q - 3
VEHICLE THEFT SECURITY (Continued)

these outputs vary by the requirements of the mar-
ket for which the vehicle is manufactured. In all
cases, the visual output will be a flashing on and off
of the exterior lamps. For vehicles equipped with the
North American or the ROW base version of the
VTA, the audible output will be a pulsing of the horn.
For vehicles with the ROW premium version of the
VTA, the audible output will be a cycling of the
alarm siren. See the owner's manual in the vehicle
glove box for details of the alarm output require-
ments of the specific market for which the vehicle
was manufactured. The inputs that will trigger the
alarm include the door ajar switches, the tailgate
ajar switch, the flip-up glass ajar switch, and in vehi-
cles built for certain markets where they are
required, the hood ajar switch and the Intrusion
Transceiver Module (ITM).
²TAMPER ALERT- The VTA tamper alert fea-
ture will pulse the horn (or the alarm siren for the
ROW premium version of the VTA) three times upon
VTA disarming, if the alarm was triggered and has
since timed-out. This feature alerts the vehicle oper-
ator that the VTA alarm was activated while the
vehicle was unattended.
²INTRUSION ALARM- The intrusion alarm is
an exclusive feature of the ROW premium version of
the VTA, which is only available in certain markets
where it is required. When the VTA is armed, a
motion sensor in the Intrusion Transceiver Module
(ITM) monitors the interior of the vehicle for move-
ment. If motion is detected, the ITM sends an elec-
tronic message to the BCM over the PCI data bus to
invoke the visual alarm feature, and sends an elec-
tronic message to the alarm siren in the engine com-
partment over a dedicated serial bus to invoke the
audible alarm feature. The motion detect feature of
the ITM can be disabled by depressing the ªLockº
button on the RKE transmitter three times within
fifteen seconds during VTA arming, while the secu-
rity indicator is still flashing rapidly. The VTA pro-
vides a single short siren ªchirpº as an audible
confirmation that the motion detect disable request
has been received. The ITM must be electronically
enabled in order for the intrusion alarm to perform
as designed. The logic in the ITM keeps its intrusion
alarm function dormant until it is enabled using a
DRBIIItscan tool. The intrusion alarm function of
the ITM is enabled on vehicles equipped with thisoption at the factory, but a service replacement ITM
must be configured and enabled by the dealer using a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
SENTRY KEY IMMOBILIZER SYSTEM The Sen-
try Key Immobilizer System (SKIS) is designed to
provide passive protection against unauthorized vehi-
cle use by disabling the engine after about two sec-
onds of running, whenever any method other than a
valid Sentry Key is used to start the vehicle. The
SKIS is considered a passive protection system
because it is always active when the ignition system
is energized and does not require any customer inter-
vention. The SKIS uses Radio Frequency (RF) com-
munication to obtain confirmation that the key in the
ignition switch is a valid key for operating the vehi-
cle. The microprocessor-based SKIS hardware and
software also use electronic messages to communi-
cate with other electronic modules in the vehicle over
the Programmable Communications Interface (PCI)
data bus. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/COMMUNICATION - OPER-
ATION).
Pre-programmed Sentry Key transponders are pro-
vided with the vehicle from the factory. Each Sentry
Key Immobilizer Module (SKIM) will recognize a
maximum of eight Sentry Keys. If the customer
would like additional keys other than those provided
with the vehicle, they may be purchased from any
authorized dealer. These additional keys must be pro-
grammed to the SKIM in the vehicle in order for the
system to recognize them as valid keys. This can be
done by the dealer using a DRBIIItscan tool or, if
Customer Learn programming is an available SKIS
feature in the market where the vehicle was pur-
chased, the customer can program the additional
keys, as long as at least two valid Sentry Keys are
already available. (Refer to 8 - ELECTRICAL/VEHI-
CLE THEFT SECURITY - STANDARD PROCE-
DURE - TRANSPONDER PROGRAMMING).
The SKIS performs a self-test each time the igni-
tion switch is turned to the On position, and will
store fault information in the form of Diagnostic
Trouble Codes (DTC's) if a system malfunction is
detected. The SKIS can be diagnosed, and any stored
DTC's can be retrieved using a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
KJVEHICLE THEFT SECURITY 8Q - 5
VEHICLE THEFT SECURITY (Continued)

continuity. If OK, go to Step 6. If not OK, repair the
open ground circuit(s) to ground (G202) as required.
(6) Reconnect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
instrument panel wire harness connector for the
SKIM. If OK, go to Step 7. If not OK, repair the open
fused B(+) circuit between the SKIM and the JB as
required.
(7) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run-start) circuit cavity of the instrument
panel wire harness connector for the SKIM. If OK,
use a DRBIIItscan tool to complete the diagnosis of
the SKIS. Refer to the appropriate diagnostic infor-
mation. If not OK, repair the open fused ignition
switch output (run-start) circuit between the SKIM
and the JB as required.
SKIS INDICATOR FLASHES UPON IGNITION ªONº OR
LIGHTS SOLID FOLLOWING BULB TEST
A SKIS indicator that flashes following the ignition
switch being turned to the On position indicates that
an invalid key has been detected, or that a key-re-
lated fault has been set. A SKIS indicator that lights
solid following a successful bulb test indicates that
the SKIM has detected a system malfunction or that
the SKIS is inoperative. In either case, fault informa-
tion will be stored in the SKIM memory. For retrieval
of this fault information and further diagnosis of the
SKIS, the PCI data bus, the SKIM electronic mes-
sage outputs to the instrument cluster that control
the SKIS indicator and chime, or the electronic mes-
sage inputs and outputs between the SKIM and the
Powertrain Control Module (PCM) that control
engine operation, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information. Fol-
lowing are preliminary troubleshooting guidelines to
be followed during diagnosis using a DRBIIItscan
tool:
(1) Using the DRBIIItscan tool, read and record
the faults as they exist in the SKIM when you first
begin your diagnosis of the vehicle. It is important to
document these faults because the SKIM does not
differentiate between historical faults (those that
have occurred in the past) and active faults (those
that are currently present). If this problem turns out
to be an intermittent condition, this information may
become invaluable to your diagnosis.
(2) Using the DRBIIItscan tool, erase all of the
faults from the SKIM.
(3) Cycle the ignition switch to the Off position,
then back to the On position.
(4) Using the DRBIIItscan tool, read any faults
that are now present in the SKIM. These are the
active faults.(5) Using this active fault information, refer to the
proper procedure in the appropriate diagnostic infor-
mation for the specific additional diagnostic steps.
STANDARD PROCEDURE
STANDARD PROCEDURE - SKIS
INITIALIZATION
The Sentry Key Immobilizer System (SKIS) must
be initialized following a Sentry Key Immobilizer
Module (SKIM) replacement. SKIS initialization
requires the use of a DRBIIItscan tool. Initialization
will also require that you have access to the unique
four-digit PIN code that was assigned to the original
SKIM. The PIN codemustbe used to enter the
Secured Access Mode in the SKIM. This PIN number
may be obtained from the vehicle owner, from the
original vehicle invoice, or from the DaimlerChrysler
Customer Center. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES - STANDARD PRO-
CEDURE - PCM/SKIM PROGRAMMING).
NOTE: If a Powertrain Control Module (PCM) is
replaced on a vehicle equipped with the Sentry Key
Immobilizer System (SKIS), the unique Secret Key
data must be transferred from the Sentry Key
Immobilizer Module (SKIM) to the new PCM using
the PCM replacement procedure. This procedure
also requires the use of a DRBIIITscan tool and the
unique four-digit PIN code to enter the Secured
Access Mode in the SKIM. Refer to the appropriate
diagnostic information for the proper PCM replace-
ment procedures.
STANDARD PROCEDURE - SENTRY KEY
TRANSPONDER PROGRAMMING
All Sentry Keys included with the vehicle are pre-
programmed to work with the Sentry Key Immobi-
lizer System (SKIS) when it is shipped from the
factory. The Sentry Key Immobilizer Module (SKIM)
can be programmed to recognize up to a total of eight
Sentry Keys. When programming a blank Sentry Key
transponder, the key must first be cut to match the
ignition switch lock cylinder in the vehicle for which
it will be used. Once the additional or new key has
been cut, the SKIM must be programmed to recog-
nize it as a valid key. There are two possible methods
to program the SKIM to recognize a new or addi-
tional valid key, the Secured Access Method and the
Customer Learn Method. Following are the details of
these two programming methods.
8Q - 8 VEHICLE THEFT SECURITYKJ
VEHICLE THEFT SECURITY (Continued)

electronic circuitry of the ITM which includes a
microprocessor, and an ultrasonic receive transducer.
A molded plastic connector receptacle containing six
terminal pins that is soldered to a small circuit board
and extends through a clearance hole in the left front
corner of the ITM housing, and an ultrasonic trans-
mit transducer housing extends from the center of
the right side of the ITM housing. Both the transmit
transducer on the right side of the module and the
receive transducer on the ITM circuit board are
aimed through two small round holes in the sight
shield of the trim cover. The ITM is connected to the
vehicle electrical system by a dedicated take out and
connector of the overhead wire harness that is inte-
gral to the headliner.
The ITM unit cannot be adjusted or repaired and,
if faulty or damaged, it must be replaced. The ITM is
serviced as a unit with the trim cover.
OPERATION
The microprocessor in the Intrusion Transceiver
Module (ITM) contains the motion sensor logic cir-
cuits and controls all of the features of the premium
version of the Vehicle Theft Alarm (VTA). The ITM
uses On-Board Diagnostics (OBD) and can communi-
cate with other electronic modules in the vehicle as
well as with the DRBIIItscan tool using the Pro-
grammable Communications Interface (PCI) data bus
network. This method of communication is used by
the ITM to communicate with the Body Control Mod-
ule (BCM) and for diagnosis and testing through the
16-way data link connector located on the driver side
lower edge of the instrument panel. The ITM also
communicates with the alarm siren over a dedicated
serial bus circuit.
The ITM microprocessor continuously monitors
inputs from its on-board motion sensor circuitry as
well as inputs from the BCM and the alarm siren
module. The on-board ITM motion sensor circuitry
transmits ultrasonic signals into the vehicle cabin
through a transmit transducer, then listens to the
returning signals as the bounce off of objects in the
vehicle interior. If an object is moving in the interior,
a detection circuit in the ITM senses this movement
through the modulation of the returning ultrasonic
signals that occurs due to the Doppler effect. The
motion detect function of the ITM can be disabled by
depressing the ªLockº button on the Remote Keyless
Entry (RKE) transmitter three times within fifteen
seconds, while the security indicator is still flashing
rapidly. The ITM will signal the alarm siren module
to provide a single siren ªchirpº as an audible confir-
mation that the motion sensor function has been dis-
abled.
If movement is detected, the ITM sends an elec-
tronic message to the BCM over the PCI data bus toflash the exterior lighting and sends an electronic
message to the alarm siren module over a dedicated
serial bus line to sound the siren. When the BCM
detects a breach in the perimeter protection through
a door, tailgate, flip-up glass, or hood ajar switch
input, it sends an electronic message to the ITM and
the ITM sends an electronic message to the BCM
over the PCI data bus to flash the exterior lighting
and sends an electronic message to the alarm siren
module over a dedicated serial bus line to sound the
siren. The ITM also monitors inputs from the alarm
siren module for siren battery or siren input/output
circuit tamper alerts, and siren battery condition
alerts, then sets active and stored Diagnostic Trouble
Codes (DTC) for any monitored system faults it
detects. An active fault only remains for the current
ignition switch cycle, while a stored fault causes a
DTC to be stored in memory by the ITM. If a fault
does not recur for fifty ignition cycles, the ITM will
automatically erase the stored DTC.
The ITM is connected to the vehicle electrical sys-
tem through a dedicated take out and connector of
the overhead wire harness. The ITM receives battery
current on a fused B(+) circuit through a fuse in the
Junction Block (JB), and receives ground through a
ground circuit and take out of the body wire harness.
This ground take out has a single eyelet terminal
connector that is secured by a ground screw to the
base of the left D-pillar behind the quarter trim
panel. These connections allow the ITM to remain
operational, regardless of the ignition switch position.
The hard wired inputs and outputs for the ITM may
be diagnosed and tested using conventional diagnos-
tic tools and procedures. However, conventional diag-
nostic methods will not prove conclusive in the
diagnosis of the ITM, the PCI data bus network, or
the electronic message inputs to and outputs from
the ITM. The most reliable, efficient, and accurate
means to diagnose the ITM, the PCI data bus net-
work, and the electronic message inputs to and out-
puts from the ITM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) While pulling downward lightly on either rear
corner of the Intrusion Transceiver Module (ITM)
trim cover, insert a small thin-bladed screwdriver
through each of the service holes on the rear edge of
the trim cover to depress and release the two inte-
gral rear latch features of the module from the
mounting bracket above the headliner (Fig. 11).
(3) Pull the ITM trim cover rearward far enough
to disengage the two integral front latch features of
KJVEHICLE THEFT SECURITY 8Q - 15
INTRUSION TRANSCEIVER MODULE (Continued)

An electrically operated intermittent front wiper
and washer system is standard factory-installed
safety equipment on this model (Fig. 1). The front
wiper and washer system includes the following
major components, which are described in further
detail elsewhere in this service information:
²Body Control Module- The Body Control
Module (BCM) is located on the Junction Block (JB)
under the driver side outboard end of the instrument
panel. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/BODY CONTROL MODULE
- DESCRIPTION).
²Front Check Valve- The front washer system
check valve is integral to the wye fitting located in
the washer plumbing between the cowl plenum
washer hose and the front washer nozzles, and is
concealed beneath the cowl plenum cover/grille panel
at the base of the windshield.
²Front Washer Nozzle- Two fluidic front
washer nozzles are secured with integral snap fea-
tures to dedicated openings in the cowl plenum cover/
grille panel located near the base of the windshield.
²Front Washer Plumbing- The plumbing for
the front washer system consists of rubber hoses and
molded plastic fittings. The plumbing is routed along
the right side of the engine compartment from the
washer reservoir, and through the dash panel into
the cowl plenum to the front washer nozzle fittings
beneath the cowl plenum cover/grille panel.
²Front Wiper Arm- The two front wiper arms
are secured with nuts to the threaded studs on the
ends of the two wiper pivot shafts, which extend
through the cowl plenum cover/grille panel located
near the base of the windshield.
²Front Wiper Blade- The two front wiper
blades are secured to the two front wiper arms with
an integral latch, and are parked on the glass near
the bottom of the windshield when the front wiper
system is not in operation.
²Front Wiper Module- The front wiper pivot
shafts are the only visible components of the front
wiper module. The remainder of the module is con-
cealed within the cowl plenum area beneath the cowl
plenum cover/grille panel. The front wiper module
includes the wiper module bracket, four rubber-iso-
lated wiper module mounts, the front wiper motor,
the wiper motor crank arm, the two wiper drive
links, and the two front wiper pivots.
²Multi-Function Switch- The multi-function
switch is located on the top of the steering column,
just below the steering wheel. The multi-function
switch includes a left (lighting) control stalk and a
right (wiper) control stalk. The right control stalk is
dedicated to providing all of the driver controls for
both the front and rear wiper systems. (Refer to 8 -ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
MULTI-FUNCTION SWITCH - DESCRIPTION).
²Washer Fluid Level Switch- The washer fluid
level switch is located in a dedicated hole near the
center of the rearward facing surface of the washer
reservoir, behind the right front wheel house splash
shield.
²Washer Pump/Motor- The reversible electric
washer pump/motor unit is located in a dedicated
hole on the lower outboard side of the washer reser-
voir, behind the right front wheel house splash
shield. This single reversible washer pump/motor
provides washer fluid to either the front or rear
washer system plumbing, depending upon the direc-
tion of the pump motor rotation.
²Washer Reservoir- The washer reservoir is
concealed behind the right front wheel house splash
shield ahead of the right front wheel. The washer
reservoir filler neck is the only visible portion of the
reservoir, and it is accessed from the right front cor-
ner of the engine compartment.
²Wiper High-Low Relay- The wiper high-low
relay is an International Standards Organization
(ISO) micro relay located in the Power Distribution
Center (PDC) in the engine compartment near the
battery.
²Wiper On-Off Relay- The wiper on-off relay is
an International Standards Organization (ISO) micro
relay located in the Power Distribution Center (PDC)
in the engine compartment near the battery.
Hard wired circuitry connects the front wiper and
washer system components to 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 connected to each other, to the
vehicle electrical system and to the front wiper and
washer system components through the use of a com-
bination of soldered splices, splice block connectors,
and many different types of wire harness terminal
connectors and insulators. 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.
OPERATING MODES The components of the front
wiper and washer system are designed to work in
concert to provide the following operating modes:
²Continuous Wipe Mode- The control knob on
the right (wiper) control stalk of the multi-function
switch has two continuous wipe positions, Low and
High. When selected, these switch positions will
cause the two-speed front wiper motor to operate in a
continuous low or high speed cycle.
KJFRONT WIPERS/WASHERS 8R - 3
FRONT WIPERS/WASHERS (Continued)