2002 JEEP GRAND CHEROKEE Power

NOTE: Vehicles equipped with a three-point center
seat belt have the center seat belt lower anchor
secured to the right buckle anchor plate with a
screw instead of the center lap belt. (Refer to 8 -
ELECTRICAL/RESTRAINTS/REAR CENTER SEAT
BELT & RETRACTOR - INSTALLATION).
(3) Fold the rear seat cushion back into the seat-
ing position.
SEAT BELT SWITCH
DESCRIPTION
The seat belt switch for this model is actually a
Hall Effect-type sensor. This sensor consists of a
fixed-position, Hall Effect Integrated Circuit (IC) chip
and a small permanent magnet that are integral to
each front seat belt buckle. The front seat belt buck-
les are each located on a stamped steel stanchion
within a molded plastic scabbard and secured with a
screw to the floor panel transmission tunnel on the
inboard side of each front seat cushion (Fig. 40). Theseat belt switches are connected to the vehicle elec-
trical system through a two-lead pigtail wire and
connector on the seat belt buckle-half, which is con-
nected to a wire harness connector and take out of
the body wire harness on vehicles with manual seat
adjusters, or to a connector and take out of the power
seat wire harness on vehicles with power seat adjust-
ers. A radio noise suppression capacitor is connected
in parallel with the IC where the two pigtail wire
leads connect to the IC pins.
The seat belt switch cannot be adjusted or repaired
and, if faulty or damaged, the entire seat belt buckle-
half unit must be replaced.
OPERATION
The seat belt switches are designed to provide a
status signal to the seat belt switch sense inputs of
the Airbag Control Module (ACM) indicating whether
the front seat belts are fastened. The ACM uses the
seat belt switch inputs as a factor in determining
what level of force with which it should deploy the
multistage driver and passenger airbags. In addition,
the ACM sends electronic messages to the ElectroMe-
chanical Instrument Cluster (EMIC) to control the
seat belt indicator based upon the status of the
driver side front seat belt switch. A spring-loaded
slide with a small window-like opening is integral to
the buckle latch mechanism. When a seat belt tip-
half is inserted and latched into the seat belt buckle,
the slide is pushed downward and the window of the
slide exposes the Hall Effect Integrated Circuit (IC)
chip within the buckle to the field of the permanent
magnet, which induces a current within the chip.
The chip provides this induced current as an output
to the ACM, which monitors the current to determine
the status of the front seat belts. When the seat belt
is unbuckled, the spring-loaded slide moves upward
and shields the IC from the field of the permanent
magnet, causing the output current from the seat
belt switch to be reduced.
The seat belt switch receives a supply current from
the ACM, and the ACM senses the status of the front
seat belts through its pigtail wire connection to the
airbag overlay wire harness. The ACM monitors the
condition of the seat belt switch circuits and will illu-
minate the airbag indicator in the EMIC then store a
Diagnostic Trouble Code (DTC) for any fault that is
detected in either seat belt switch circuit. For proper
diagnosis of the seat belt switches, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
Fig. 40 Front Seat Belt Buckle
1 - SEAT BELT BUCKLE
2 - SEAT BELT SWITCH PIGTAIL WIRE
3 - SCREW
WJRESTRAINTS 8O - 37
REAR SEAT BELT BUCKLE (Continued)

²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
Once the speed control has been disengaged,
depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the PCM.
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
PCM when the RES/ACCEL is released. The PCM
also has a9tap-up9feature in which vehicle speed
increases at a rate of approximately 2 mph for each
momentary switch activation of the RES/ACCEL
switch.
A ªtap downº feature is used to decelerate without
disengaging the speed control system. To decelerate
from an existing recorded target speed, momentarily
depress the COAST switch. For each switch activa-
tion, speed will be lowered approximately 1 mph.
OVERSHOOT/UNDERSHOOT
If the vehicle operator repeatedly presses and
releases the SET button with their foot off of the
accelerator (referred to as a ªlift foot setº), the vehicle
may accelerate and exceed the desired set speed by
up to 5 mph (8 km/h). It may also decelerate to less
than the desired set speed, before finally achieving
the desired set speed.
The Speed Control System has an adaptive strat-
egy that compensates for vehicle-to-vehicle variations
in speed control cable lengths. When the speed con-
trol is set with the vehicle operators foot off of the
accelerator pedal, the speed control thinks there is
excessive speed control cable slack and adapts
accordingly. If the ªlift foot setsº are continually used,
a speed control overshoot/undershoot condition will
develop.
To ªunlearnº the overshoot/undershoot condition,
the vehicle operator has to press and release the set
button while maintaining the desired set speed using
the accelerator pedal (not decelerating or accelerat-
ing), and then turning the cruise control switch to
the OFF position (or press the CANCEL button if
equipped) after waiting 10 seconds. This procedure
must be performed approximately 10±15 times to
completely unlearn the overshoot/undershoot condi-
tion.DIAGNOSIS AND TESTING - ROAD TEST
Perform a vehicle road test to verify reports of
speed control system malfunction. The road test
should include attention to the speedometer. Speed-
ometer operation should be smooth and without flut-
ter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to Group 8J,
Instrument Cluster for speedometer diagnosis.
If a road test verifies a system problem and the
speedometer operates properly, check for:
²A Diagnostic Trouble Code (DTC). If a DTC
exists, conduct tests per the Powertrain Diagnostic
Procedures service manual.
²A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
²Loose, damaged or corroded electrical connec-
tions at the servo. Corrosion should be removed from
electrical terminals and a light coating of Mopar
MultiPurpose Grease, or equivalent, applied.
²Leaking vacuum reservoir.
²Loose or leaking vacuum hoses or connections.
²Defective one-way vacuum check valve.
²Secure attachment of both ends of the speed con-
trol servo cable.
²Smooth operation of throttle linkage and throttle
body air valve.
²Failed speed control servo. Do the servo vacuum
test.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals or seals. If
these components are damaged, intermittent or
complete system failure may occur.
8P - 2 SPEED CONTROLWJ
SPEED CONTROL (Continued)

(8) Connect negative battery cable at battery.
(9) Before starting engine, operate accelerator
pedal to check for any binding.
SERVO
DESCRIPTION
The servo unit consists of a solenoid valve body,
and a vacuum chamber. The solenoid valve body con-
tains three solenoids:
²Vacuum
²Vent
²Dump
The vacuum chamber contains a diaphragm with a
cable attached to control the throttle linkage.
OPERATION
The Powertrain Control Module (PCM) controls the
solenoid valve body. The solenoid valve body controls
the application and release of vacuum to the dia-
phragm of the vacuum servo. The servo unit cannot
be repaired and is serviced only as a complete assem-
bly.
Power is supplied to the servo's by the PCM
through the brake switch. The PCM controls the
ground path for the vacuum and vent solenoids.The dump solenoid is energized anytime it receives
power. If power to the dump solenoid is interrupted,
the solenoid dumps vacuum in the servo. This pro-
vides a safety backup to the vent and vacuum sole-
noids.
The vacuum and vent solenoids must be grounded
at the PCM to operate. When the PCM grounds the
vacuum servo solenoid, the solenoid allows vacuum
to enter the servo and pull open the throttle plate
using the cable. When the PCM breaks the ground,
the solenoid closes and no more vacuum is allowed to
enter the servo. The PCM also operates the vent sole-
noid via ground. The vent solenoid opens and closes a
passage to bleed or hold vacuum in the servo as
required.
The PCM duty cycles the vacuum and vent sole-
noids to maintain the set speed, or to accelerate and
decelerate the vehicle. To increase throttle opening,
the PCM grounds the vacuum and vent solenoids. To
decrease throttle opening, the PCM removes the
grounds from the vacuum and vent solenoids. When
the brake is released, if vehicle speed exceeds 30
mph to resume, 35 mph to set, and the RES/ACCEL
switch has been depressed, ground for the vent and
vacuum circuits is restored.
REMOVAL
The speed control servo is attached to a bracket.
The bracket and servo assembly are located below
the battery tray.
(1) Disconnect negative battery cable at battery.
(2) Disconnect positive battery cable at battery.
(3) Remove air cleaner housing at top of throttle
body and disconnect servo cable at throttle body.
Refer to Servo Cable Removal/Installation.
(4) Remove battery from battery tray.
(5) Disconnect wiring at battery tray.
(6) Disconnect positive battery cable at Power Dis-
tribution Center (PDC).
(7) Loosen PDC at battery tray.
(8) Remove 4 battery tray bolts. One of these bolts
attaches to speed control bracket flange that sup-
ports battery tray. While removing battery tray, dis-
connect battery temperature sensor electrical
connector at sensor.
(9) Disconnect vacuum line at servo vacuum hose
fitting (Fig. 5) .
(10) Disconnect electrical connector at servo (Fig.
5) .
If servo and mounting bracket are being removed
as one assembly, remove two mounting nuts (Fig. 5) .
These are located above right-front tire. Remove
inner fender clips and pry inner fender back slightly
to gain access to mounting nuts.
Fig. 4 Speed Control Cable at BracketÐ4.7L V-8
Engine
1 - PLASTIC CABLE MOUNT
2 - SPEED CONTROL CABLE
3 - BRACKET
4 - SLIDE FOR REMOVAL
WJSPEED CONTROL 8P - 5
CABLE (Continued)

(11) If servo is being removed from its mounting
bracket, remove 2 mounting nuts holding servo cable
sleeve to bracket (Fig. 6) .
(12) Pull speed control cable sleeve and servo away
from servo mounting bracket to expose cable retain-
ing clip (Fig. 6) and remove clip. Note: The servo
mounting bracket displayed in (Fig. 6) is a typical
bracket and may/may not be applicable to this model
vehicle.
(13) Remove servo from mounting bracket or,
remove servo and mounting bracket as one assembly.
INSTALLATION
(1) Position servo to mounting bracket.
(2) Align hole in cable connector with hole in servo
pin. Install cable-to-servo retaining clip.
(3) Insert servo mounting studs through holes in
servo mounting bracket.
(4) Install servo cable mounting nuts (Fig. 6) and
tighten to 8.5 N´m (75 in. lbs.) torque. If servo and
bracket is being installed as one assembly, install 2
mounting nuts (Fig. 5) and tighten to 28 N´m  6 N´m
(250 in. lbs.  50 in. lbs.) torque.
(5) Connect vacuum line at servo.
(6) Connect electrical connector at servo.
(7) Connect servo cable to throttle body. Refer to
Servo Cable Removal/Installation.
(8) Install battery tray and battery temperature
sensor.
(9) Connect wiring to battery tray.
(10) Install battery to battery tray.
(11) Connect positive battery cable to Power Distri-
bution Center (PDC).
(12) Connect positive battery cable to battery.
(13) Connect negative battery cable to battery.
(14) Before starting engine, operate accelerator
pedal to check for any binding.
Fig. 5 Speed Control
1 - VACUUM HOSE FITTING
2 - SPEED CONTROL SERVO
3 - SERVO CABLE
4 - RIGHT INNER FENDER
5 - SERVO MOUNTING NUTS (2)
6 - SERVO MOUNTING BRACKET
7 - ELEC. CONNECTOR
Fig. 6 Servo Cable Clip Remove/InstallÐTypical
1 - SERVO MOUNTING NUTS (2)
2 - SERVO
3 - CABLE RETAINING CLIP
4 - SERVO CABLE AND SLEEVE
8P - 6 SPEED CONTROLWJ
SERVO (Continued)

SWITCH
DESCRIPTION
There are two separate switch pods that operate
the speed control system. The steering-wheel-
mounted switches use multiplexed circuits to provide
inputs to the PCM for ON, OFF, RESUME, ACCEL-
ERATE, SET, DECEL and CANCEL modes. Refer to
the owner's manual for more information on speed
control switch functions and setting procedures.
The individual switches cannot be repaired. If one
switch fails, the entire switch module must be
replaced.
OPERATION
When speed control is selected by depressing the
ON, OFF switch, the PCM allows a set speed to be
stored in its RAM for speed control. To store a set
speed, depress the SET switch while the vehicle is
moving at a speed between approximately 35 and 85
mph. In order for the speed control to engage, the
brakes cannot be applied, nor can the gear selector
be indicating the transmission is in Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal
²Depressing the OFF switch
²Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
²An indication of Park or Neutral
²The VSS signal increases at a rate of 10 mph
per second (indicates that the co-efficient of friction
between the road surface and tires is extremely low)
²Depressing the clutch pedal.
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The VSS signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
²If the actual speed is not within 20 mph of the
set speed
The previous disengagement conditions are pro-
grammed for added safety.
Once the speed control has been disengaged,
depressing the ACCEL switch restores the vehicle to
the target speed that was stored in the PCM's RAM.
NOTE: Depressing the OFF switch will erase the set
speed stored in the PCM's RAM.
If, while the speed control is engaged, the driver
wishes to increase vehicle speed, the PCM is pro-
grammed for an acceleration feature. With the
ACCEL switch held closed, the vehicle accelerates
slowly to the desired speed. The new target speed is
stored in the PCM's RAM when the ACCEL switch isreleased. The PCM also has a9tap-up9feature in
which vehicle speed increases at a rate of approxi-
mately 2 mph for each momentary switch activation
of the ACCEL switch.
The PCM also provides a means to decelerate with-
out disengaging speed control. To decelerate from an
existing recorded target speed, depress and hold the
COAST switch until the desired speed is reached.
Then release the switch. The ON, OFF switch oper-
ates two components: the PCM's ON, OFF input, and
the battery voltage to the brake switch, which powers
the speed control servo.
Multiplexing
The PCM sends out 5 volts through a fixed resistor
and monitors the voltage change between the fixed
resistor and the switches. If none of the switches are
depressed, the PCM will measure 5 volts at the sen-
sor point (open circuit). If a switch with no resistor is
closed, the PCM will measure 0 volts (grounded cir-
cuit). Now, if a resistor is added to a switch, then the
PCM will measure some voltage proportional to the
size of the resistor. By adding a different resistor to
each switch, the PCM will see a different voltage
depending on which switch is pushed.
Another resistor has been added to the 'at rest cir-
cuit' causing the PCM to never see 5 volts. This was
done for diagnostic purposes. If the switch circuit
should open (bad connection), then the PCM will see
the 5 volts and know the circuit is bad. The PCM will
then set an open circuit fault.
REMOVAL
WARNING: BEFORE BEGINNING ANY AIRBAG SYS-
TEM COMPONENT REMOVAL OR INSTALLATION,
REMOVE AND ISOLATE THE NEGATIVE (-) CABLE
FROM THE BATTERY. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. THEN
WAIT TWO MINUTES FOR SYSTEM CAPACITOR TO
DISCHARGE BEFORE FURTHER SYSTEM SERVICE.
FAILURE TO DO THIS COULD RESULT IN ACCIDEN-
TAL AIRBAG DEPLOYMENT AND POSSIBLE
INJURY.
(1) Disconnect and isolate negative battery cable.
(2) Remove airbag module. Refer to Group 8M,
Passive Restraint Systems.
(3) Remove electrical connector at switch.
(4) Remove switch-to-steering wheel mounting
screw (Fig. 7) .
(5) Remove switch.
INSTALLATION
(1) Install switch and mounting screw.
(2) Tighten screw to 1.5 N´m (15 in. lbs.) torque.
(3) Install electrical connector to switch.
WJSPEED CONTROL 8P - 7

CONTROL/CENTRAL TIMER MODULE -
DESCRIPTION).
²Combination Flasher (Refer to 8 - ELECTRI-
CAL/LAMPS/LIGHTING - EXTERIOR/COMBINA-
TION FLASHER - DESCRIPTION).
²Door Ajar Switch (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/DOOR AJAR
SWITCH - DESCRIPTION - DOOR AJAR SWITCH).
²Driver Cylinder Lock Switch (Refer to 8 - ELEC-
TRICAL/POWER LOCKS/DOOR CYLINDER LOCK/
UNLOCK SWITCH - DESCRIPTION).
²Hood Ajar Switch(Refer to 8 - ELECTRICAL/VE-
HICLE THEFT SECURITY/HOOD AJAR SWITCH -
DESCRIPTION).
²Horn Relay (Refer to 8 - ELECTRICAL/HORN/
HORN RELAY - DESCRIPTION).
²Liftgate Ajar Switch (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/DOOR AJAR
SWITCH - DESCRIPTION - LIFTGATE AJAR
SWITCH).
²Liftgate Flip-Up Glass Ajar Switch(Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - INTERIOR/
DOOR AJAR SWITCH - DESCRIPTION - LIFTGATE
FLIP-UP GLASS AJAR SWITCH).
²Low Beam Headlamp Relay
²VTSS Indicator (Refer to 8 - ELECTRICAL/VE-
HICLE THEFT SECURITY/VTSS INDICATOR -
DESCRIPTION).
Certain functions and features of the VTSS rely
upon resources shared with or controlled by other
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
other modules that may affect VTSS operation are:
²Driver Door Module (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/DOOR MOD-
ULE - DESCRIPTION).
²Passenger Door Module (Refer to 8 - ELECTRI-
CAL/ELECTRONIC CONTROL MODULES/DOOR
MODULE - DESCRIPTION).
DESCRIPTION - SENTRY KEY IMMOBILIZER
SYSTEM
Vehicles equipped with the Sentry Key Immobilizer
System (SKIS) can be identified by the presence of
an amber SKIS indicator in the instrument cluster
that will illuminate for about three seconds each
time the ignition switch is turned to the On position,
or by a gray molded rubber cap on the head of the
ignition key. Models not equipped with SKIS still
have a SKIS indicator in the cluster, but it will not
illuminate. Also, models not equipped with the SKIS
have a black molded rubber cap on the head of the
ignition key.
The SKIS includes the following major components,
which are described in further detail elsewhere in
this service manual:²Powertrain Control Module
²Sentry Key Immobilizer Module
²Sentry Key Transponder
²SKIS Indicator
Except for the Sentry Key transponders, which rely
upon Radio Frequency (RF) communication, hard
wired circuitry connects the SKIS components to the
electrical system of the vehicle.Refer to the appropri-
ate wiring information.
OPERATION
OPERATION - VEHICLE THEFT SECURITY
SYSTEM
The Vehicle Theft Security System (VTSS) is
divided into two basic subsystems: Vehicle Theft
Alarm (VTA) and Sentry Key Immobilizer System
(SKIS). The following are paragraphs that briefly
describe the operation of each of those two sub-
systems.
A Body Control Module (BCM) is used to control
and integrate many of the functions and features
included in the Vehicle Theft Security System
(VTSS). In the VTSS, the BCM receives inputs indi-
cating the status of the door ajar switches, the driver
cylinder lock switch, the ignition switch, the liftgate
ajar switches, the liftgate flip-up glass ajar switch,
the power lock switches and, in vehicles so equipped,
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-
ergize the combination flasher, the horn relay (except
vehicles with the premium version of the VTA), and
the VTSS indicator. In addition, in vehicles built for
certain markets where premium versions of the VTA
is required, the BCM also exchanges messages with
the Intrusion Transceiver Module (ITM) over the Pro-
grammable Communications Interface (PCI) data
buss network to provide the features found in this
version of the VTA. The control of these inputs and
outputs are what constitute all of the features of the
VTSS. Following is information on the operation of
each of the VTSS features.
ENABLING
The BCM must have the VTSS function enabled in
order for the VTSS to perform as designed. The logic
in the BCM keeps its VTSS function dormant until it
is enabled using a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
PRE-ARMING
The VTA has a pre-arming sequence. Pre-arming
occurs when a door, the tailgate, or the flip-up glass
is open when the vehicle is locked using a power lock
8Q - 2 VEHICLE THEFT SECURITYWJ
VEHICLE THEFT SECURITY (Continued)

switch, or when the ªLockº button on the Remote
Keyless Entry (RKE) transmitter is depressed. The
powerlock switch will not initiate the pre-arming
sequence if the key is in the ignition switch. When
the VTA is pre-armed, the arming sequence is
delayed until all of the doors, the tailgate and the
flip-up glass are closed.
ARMING
Passive arming of the VTSS occurs when the vehi-
cle is exited with the key removed from the ignition
switch, the headlamps are turned off, and the doors
are locked while they are open using the power lock
switch. The power lock switch will not function if the
key is in the ignition switch or the headlamps are
turned on with the driver side front door open. The
VTSS will not arm if the driver side front door is
locked using the key in the lock cylinder or using the
mechanical lock button. Active arming of the VTSS
occurs when the ªLockº button on the Remote Key-
less Entry (RKE) transmitter is depressed to lock the
vehicle, even if the doors and/or the liftgate are open
when the RKE transmitter Lock button is depressed.
However, the VTSS arming will not be complete until
all of the doors, the liftgate and the liftgate flip-up
glass are closed. On vehicles equipped with the hood
ajar switch, VTSS arming will complete if the hood is
open, but the underhood area will not be protected
unless the hood is closed when the VTSS is armed.
Following successful passive or active VTSS arm-
ing, the VTSS indicator on the top of the instrument
panel will flash rapidly for about sixteen seconds
after the illuminated entry system times out. This
indicates that VTSS arming is in progress. Once the
sixteen second arming function is successfully com-
pleted, the indicator will flash at a slower rate, indi-
cating that the VTSS is armed.
DISARMING
Passive disarming of the VTSS occurs when the
vehicle is unlocked using the key to unlock the driver
side front door. Active disarming of the VTSS occurs
when the vehicle is unlocked by depressing the
ªUnlockº button of the Remote Keyless Entry (RKE)
transmitter. Once the alarm has been activated,
either disarming method will also deactivate the
alarm. Depressing the ªPanicº button on the RKE
transmitter will also disarm the VTSS, but the horn
will continue to pulse and the exterior lamps will
continue to flash for about three minutes as part of
the Panic feature function. The Panic feature is over-
ridden if the ªPanicº button is depressed a second
time, or if a vehicle speed of about 24 kilometers-per-
hour (15 miles-per-hour) is attained.POWER-UP MODE
When the armed VTSS senses that the battery has
been disconnected and reconnected, it enters its pow-
er-up mode. In the power-up mode the alarm system
remains armed following a battery failure or discon-
nect. If the VTSS was armed prior to a battery dis-
connect or failure, the technician or vehicle operator
will have to actively or passively disarm the alarm
system after the battery is reconnected. The pow-
er-up mode will also apply if the battery goes dead
while the system is armed, and battery jump-starting
is then attempted. The VTSS will be armed until it is
actively or passively disarmed. If the VTSS is in the
disarmed mode prior to a battery disconnect or fail-
ure, it will remain disarmed after the battery is
reconnected or replaced, or if jump-starting is
attempted.
ALARM
The VTA alarm output varies by the version of the
VTA with which the vehicle is equipped. In all cases,
the alarm provides both visual and audible outputs;
however, the time intervals of these outputs vary by
the requirements of the market for which the vehicle
is manufactured. In all cases, the visual output will
be a flashing of the exterior lamps. For vehicles
equipped with North American or the base version of
the VTA, the audible output will be the pulsing of the
horn. For vehicles with the premium version of the
VTA, the audible output will be the cycling of the
siren. The inputs that will trigger the alarm include
the door ajar switch, the flip-up glass ajar switch,
and in vehicles built for certain markets where they
are required, the hood ajar switch and the Intrusion
Transceiver Module (ITM).
TAMPER ALERT
The VTSS tamper alert feature will sound the horn
(or the alarm siren for the premium version) three
times upon VTA disarming, if the alarm was trig-
gered and has since timed-out (about eighteen min-
utes). This feature alerts the vehicle operator that
the VTA alarm was activated while the vehicle was
unattended.
INTRUSION ALARM
The Intrusion Alarm is an exclusive feature of the
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 movement. If motion is detected, the
ITM sends a message to the BCM over the PCI bus
to invoke the visual alarm feature, and sends a mes-
sage to the alarm siren over a dedicated serial bus to
invoke the audible alarm feature. The motion detec-
WJVEHICLE THEFT SECURITY 8Q - 3
VEHICLE THEFT SECURITY (Continued)

(2) Check for battery voltage at the fused B(+) fuse
in the JB. If OK, go to Step 3. If not OK, repair the
open B(+) circuit between the JB fuse and the Power
Distribution Center (PDC).
(3) Check the fused ignition switch output (st-run)
fuse in the JB. If OK, go to Step 4. If not OK, repair
the shorted circuit or component and replace the
faulty fuse.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) fuse in the JB. If OK, go to Step 5. If
not OK, repair the open fused ignition switch output
(st-run) circuit between the JB fuse and the ignition
switch as required.
(5) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the Sentry Key Immobilizer Module
(SKIM) from the SKIM connector. Check for continu-
ity between the ground circuit of the instrument
panel wire harness connector for the SKIM and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit.
(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
fuse.
(7) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) circuit of the instrument panel wire
harness connector for the SKIM. If OK, refer to the
appropriate diagnostic information and use a
DRBIIItscan tool to complete the diagnosis of the
SKIS. If not OK, repair the open fused ignition
switch output (st-run) circuit between the SKIM and
the JB fuse.
SKIS INDICATOR FLASHES OR LIGHTS SOLID FOLLOWING
BULB TEST
A SKIS indicator that flashes following a successful
bulb test indicates that an invalid key has been
detected, or that a key-related fault has been set. A
SKIS indicator that lights solid following a successful
bulb test indicates that the SKIM has detected a sys-
tem malfunction or that the SKIS is inoperative. In
either case, fault information 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 message outputs to the instrument cluster,
the SKIM message outputs to the Body Control Mod-
ule (BCM), or the message inputs and outputs
between the SKIM and the Powertrain Control Mod-
ule (PCM), a DRBIIItscan tool and the appropriate
diagnostic information are required. Following 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 and active faults. If
this problem turns out to be an intermittent condi-
tion, 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 additional specific 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
8Q - 6 VEHICLE THEFT SECURITYWJ
VEHICLE THEFT SECURITY (Continued)