ECU CHRYSLER CARAVAN 2005 Owners Manual

OCCUPANT CLASSIFICATION
MODULE
DESCRIPTION
The Occupant Classification Module (OCM) (Fig.
34) is secured with two screws to a stamped steel
mounting bracket welded onto the underside of the
passenger front seat cushion frame near the inboard
front corner (Fig. 35). Concealed within a hollow in
the center of the molded plastic OCM housing is a
microprocessor and the other electronic circuitry of
the module. The module housing is sealed to enclose
and protect the internal electronic circuitry. The
OCM software is flash programmable.
A non-calibrated OCM is the only component of the
Occupant Classification System (OCS) that is avail-
able for separate service replacement. The OCS com-
ponents of the passenger side front seat cushion
including the cushion frame, insulator pad, seat
weight bladder and pressure sensor, seat cushion
foam, wiring harness and the OCM are a factory-cal-
ibrated and assembled unit. Once this unit is con-
nected to a vehicle electrically, the calibration
settings are uploaded from the calibrated OCM and
stored in the memory of the Occupant Restraint Con-
troller (ORC). If only the OCM is subsequently
replaced, the new, non-calibrated OCM learns the
proper calibration settings from the ORC after it is
connected to the vehicle electrically.The OCM cannot be adjusted or repaired and, if
damaged or faulty, it must be replaced. The compo-
nents of the passenger front seat cushion are ser-
viced only as a factory-calibrated, assembled and
tamper-evident unit. Only the OCM and the seat
cushion trim are available for separate service
replacement. Once a service replacement package has
been installed in a vehicle, the OCM can thereafter
be serviced only by replacing the entire passenger
front seat cushion with another complete service
replacement package.
OPERATION
The microprocessor in the Occupant Classification
Module (OCM) contains the Occupant Classification
System (OCS) logic circuits. The OCM uses On-Board
Diagnostics (OBD) and can communicate with other
electronic modules in the vehicle as well as with a
scan tool using the Programmable Communications
Interface (PCI) data bus network. This method of
communication is also used for OCS diagnosis and
testing through the 16-way Data Link Connector
(DLC), located on the driver side lower edge of the
instrument panel.
The OCM provides a nominal five volts to both the
pressure sensor of the seat weight bladder beneath
the passenger front seat cushion and to the belt ten-
sion sensor on the passenger front seat belt lower
Fig. 34 OCCUPANT CLASSIFICATION MODULE
(OCM) - TYPICAL
1 - OCCUPANT CLASSIFICATION MODULE
2 - CONNECTOR LOCK TOWER
3 - CONNECTOR RECEPTACLE
4 - MOUNTING TAB (2)
Fig. 35 OCM LOCATION
1 - OCCUPANT CLASSIFICATION MODULE (OCM)
2 - LOCK TOWER
3 - LOCK PIN
4 - CONNECTOR
5 - SCREW (2)
6 - BRACKET
RSRESTRAINTS8O-25

anchor. The OCM then monitors the return voltage
from each of the sensors. The bladder pressure sen-
sor input allows the OCM to determine whether the
passenger front seat is occupied and the relative size
of the occupant by providing a weight-sensing refer-
ence to the load on the seat cushion. The belt tension
sensor provides an additional logic input to the OCM
microprocessor that allows it to distinguish between
the lower seat belt cinch loads of a belted occupant
and the higher loads associated with a belted child
seat.
Pre-programmed decision algorithms and OCS cal-
ibration allow the OCM microprocessor to determine
when the seat cushion load as signaled by the blad-
der pressure sensor and the seat belt cinch load as
signaled by the belt tension sensor indicate that pas-
senger airbag protection is appropriate. When the
programmed conditions are met, the OCM sends the
proper electronic occupant classification messages
over the PCI data bus to the Occupant Restraint
Controller (ORC), and the ORC enables or disables
the deployment circuits for the passenger front sup-
plemental restraints. The ORC also provides a con-
trol output for the Passenger Airbag Disabled (PAD)
indicator in the instrument panel center stack, based
upon the electronic occupant classification messages
it receives from the OCM.
The OCM microprocessor continuously monitors all
of the OCS electrical circuits and components to
determine the system readiness. If the OCM detects
a monitored system fault, it sets an active and stored
Diagnostic Trouble Code (DTC) and sends the appro-
priate electronic messages to the ORC over the PCI
data bus. Then the ORC sets a DTC and sends mes-
sages to control the airbag indicator operation
accordingly. An active fault only remains for the
duration of the fault, or in some cases for the dura-
tion of the current ignition switch cycle, while a
stored fault causes a DTC to be stored in memory by
the OCM and the ORC. For some DTC's, if a fault
does not recur for a number of ignition cycles, the
OCM will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
The OCM receives battery current from an IPM
high side driver (Run/Start). The OCM receives
ground through a ground circuit of the body wire
harness, which it shares with the ORC. These con-
nections allow the OCM to be operational whenever
the ignition switch is in the Start or ON positions.
To diagnose and test the OCS, use a scan tool and
the appropriate diagnostic information.
REMOVAL
Once any of the original factory-installed compo-
nents except the Occupant Classification Module(OCM) have been replaced with the service replace-
ment package components, the OCM can only be ser-
viced by replacing the entire passenger front seat
cushion unit with another complete service replace-
ment package (Refer to 23 - BODY/SEATS/SEAT
CUSHION - FRONT - REMOVAL).
WARNING: Never replace both the Occupant
Restraint Controller (ORC) and the Occupant Clas-
sification Module (OCM) at the same time. If both
require replacement, replace one, then perform the
Airbag System test (Refer to 8 - ELECTRICAL/RE-
STRAINTS - DIAGNOSIS AND TESTING - AIRBAG
SYSTEM) before replacing the other. Both the ORC
and the OCM store Occupant Classification System
(OCS) calibration data, which they transfer to one
another when one of them is replaced. If both are
replaced at the same time, an irreversible fault will
be set in both modules and the OCS may malfunc-
tion and result in personal injury or death.
(1) Disconnect and isolate the battery negative
cable.
(2)
WARNING: Wait two minutes for the airbag system
reserve capacitor to discharge before beginning
any airbag system or component service. Failure to
do so may result in accidental airbag deployment,
personal injury or death.
(3) Reach under the front edge of the passenger
side front seat cushion to access and remove the lock
pin from the connector lock tower on the Occupant
Classification Module (OCM) (Fig. 36).
(4) Disconnect the passenger front seat wire har-
ness connector for the OCM.
(5) Remove the two screws that secure the OCM to
the OCM bracket.
(6) Remove the OCM from under the passenger
front seat.
INSTALLATION
WARNING: To avoid personal injury or death on
vehicles equipped with the Occupant Classification
System (OCS), only the Occupant Classification
Module (OCM) and the seat cushion trim may be
serviced separately. All other components of the
passenger front seat cushion must be serviced only
as a complete factory-calibrated, assembled and
tamper-evident service replacement package.
Once any of the original factory-installed compo-
nents except the OCM have been replaced with the
service replacement package components, the OCM
can only be serviced by replacing the entire passen-
8O - 26 RESTRAINTSRS
OCCUPANT CLASSIFICATION MODULE (Continued)

The ORC is secured with screws to a stamped steel
mounting bracket welded onto the top of the floor
panel transmission tunnel just behind and under-
neath the instrument panel center stack in the pas-
senger compartment of the vehicle (Fig. 38).
Concealed within a hollow in the center of the die
cast aluminum ORC housing is the electronic cir-
cuitry of the ORC which includes a microprocessor,
an electronic impact sensor, an electronic safing sen-
sor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ORC 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
ORC housing provides a visual verification of the
proper orientation of the unit, and should always be
pointed toward the front of the vehicle. The ORC
housing has integral mounting flanges. the ORC has
two molded plastic electrical connectors that exits the
right facing side of the ORC housing. These terminal
pins connect the ORC to the vehicle electrical system.
The impact sensor and safing sensor internal to
the ORC are calibrated for the specific vehicle, and
are only serviced as a unit with the ORC. In addi-
tion, there are unique versions of the ORC for vehi-
cles with or without curtain airbags. The ORC cannot
be repaired or adjusted and, if damaged or faulty, it
must be replaced.
OPERATION
The microprocessor in the Occupant Restraint Con-
troller (ORC) contains the supplemental restraint
system logic circuits and controls all of the supple-
mental restraint system components. The ORC uses
On-Board Diagnostics (OBD) and can communicatewith other electronic modules in the vehicle as well
as with the diagnostic scan tool using the Program-
mable Communication Interface (PCI) data bus. This
method of communication is used for control of the
airbag indicator in the ElectroMechanical Instrument
Cluster (EMIC) and for supplemental restraint sys-
tem diagnosis and testing through the 16-way Data
Link Connector (DLC) located on the driver side
lower edge of the instrument panel.
The ORC microprocessor continuously monitors all
of the supplemental restraint system electrical cir-
cuits to determine the system readiness. If the ORC
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 ORC. For some DTC's, if a fault
does not recur for a number of ignition cycles, the
ORC will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
On models equipped with the Occupant Classifica-
tion System (OCS), the ORC communicates with the
Occupant Classification Module (OCM) over the PCI
data bus. The ORC will internally disable the pas-
senger airbag and seat belt tensioner deployment cir-
cuits if the OCM detects that the passenger side
front seat is unoccupied or that it is occupied by a
load that is inappropriate for an airbag deployment.
The ORC also provides a control output to the Pas-
senger Airbag Disabled (PAD) indicator through the
passenger airbag indicator driver circuit. The OCM
notifies the ORC when it has detected a monitored
system fault and stored a DTC in its memory for any
faulty OCS component or circuit, then the ORC sets
a DTC and controls the airbag indicator operation
accordingly.
The ORC 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 ORC receives
ground through a ground circuit of the instrument
panel wire harness. These connections allow the ORC
to be operational whenever the ignition switch is in
the START or ON positions.
The ORC 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 front sup-
plemental restraint components for up to one second
following a battery disconnect or failure. The purpose
of the capacitor is to provide backup supplemental
Fig. 38 ORC LOCATION
1 - ORC ELECTRICAL CONNECTORS
2 - ORC
3 - ORC MOUNTING SCREWS
8O - 28 RESTRAINTSRS
OCCUPANT RESTRAINT CONTROLLER (Continued)

WARNING: Never replace both the Occupant
Restraint Controller (ORC) and the Occupant Clas-
sification Module (OCM) at the same time. If both
require replacement, replace one, then perform the
Airbag System test (Refer to 8 - ELECTRICAL/RE-
STRAINTS - DIAGNOSIS AND TESTING - AIRBAG
SYSTEM) before replacing the other. Both the ORC
and the OCM store Occupant Classification System
(OCS) calibration data, which they transfer to one
another when one of them is replaced. If both are
replaced at the same time, an irreversible fault will
be set in both modules and the OCS may malfunc-
tion and result in personal injury or death.
(1) Install the ORC into vehicle (Fig. 39).
(2) Connect the wire connector to the ORC (Fig.
39).
(3) Install three bolts holding ORC to floor bracket
(Fig. 39). Torque bolts to 7.3 - 9.6 N´m (65 to 85 in.
lbs.)
(4) Install the storage bin onto the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
STORAGE BIN - INSTALLATION).
WARNING: Do not connect the battery negative
cable (Refer to 8 - ELECTRICAL/RESTRAINTS -
DIAGNOSIS AND TESTING - AIRBAG SYSTEM). Per-
sonal injury or death may result if the system test
is not performed first.
(5) Verify vehicle and system operation.
(6) Close hood.
PASSENGER AIRBAG
DESCRIPTION
WARNING: Never disassemble the passenger air-
bag. The passenger airbag has no serviceable
parts. If tampered with internally, the airbag could
deploy and result in personal injury or death.
The Passenger Airbag is located beneath the
instrument panel and pad assembly. The airbag is
mounted to the back side of the instrument panel
reinforcement.
The instrument panel top pad is the most visible
part of the passenger airbag system. Located under
the instrument panel top pad are the airbag door, the
passenger airbag cushion and the airbag cushion
supporting components.
The passenger airbag includes a magnesium hous-
ing within which the cushion and inflator are
mounted and sealed.
Following a passenger airbag deployment, the pas-
senger airbag and the instrument panel must bereplaced. The passenger airbag cannot be repaired,
and must be replaced if deployed or damaged in any
way.
OPERATION
The passenger airbag is equipped with two infla-
tors, each with three levels of pressure output. The
inflators seal the hole in the airbag cushion so it can
discharge the gas it produces directly into the cush-
ion when supplied with the proper electrical signal.
Following an airbag deployment, the airbag cushion
quickly deflates by venting this gas through the
cushion material towards the instrument panel.
The passenger airbag is secured with screws to the
instrument panel beneath the instrument panel top
pad and above the glove box opening. The instrument
panel top pad above the glove box opening conceals
the airbag door and a predetermined hinge line
beneath its decorative cover. Upon airbag deploy-
ment, the top pad will bend at the hinge line and the
door will fold back out of the way onto the top of the
instrument panel.
When the front airbag system is deployed, the fol-
lowingMUSTbe replaced:
²Complete Steering Column Assembly.
²Lower Steering Column Coupler.
²Steering Wheel.
²Clock Spring.
²Driver Airbag.
²Passenger Airbag.
²Upper Instrument Panel with Pad.
CARE OF UNDEPLOYED AIRBAGS
Airbags must be stored in their original special
container until used for service. At no time should a
source of electricity be permitted near the inflator on
the back of an airbag. When carrying or handling an
undeployed airbag, the trim side of the airbag should
be pointing away from the body to minimize possibil-
ity of injury if accidental deployment occurs. Do not
place undeployed airbag face down on a solid surface,
the airbag will propel into the air if accidental
deployment occurs.
REMOVAL
DEPLOYED AIRBAG
(1) Open hood.
(2) Disconnect and isolate the battery negative
cable.
(3)
8O - 30 RESTRAINTSRS
OCCUPANT RESTRAINT CONTROLLER (Continued)

SEAT BELT TENSIONER
DESCRIPTION
The seat belt system incorporates Seat Belt Ten-
sioners. The tensioner is designed to hold the occu-
pant in their respective seat by retracting the seat
belt up to four inches. They are integral to the front
seat belt buckles and cannot be serviced. If found
defective they must be replaced. After an airbag
deployment, the tensioner must be replaced.
Seat Belt Tensioners supplement the dual front air-
bag system. The seat belt tensioners are integral to
the front seat belt buckles, which are secured to the
seat cushion frame on the inboard side. The seat belt
tensioners are controlled by the Occupant Restraint
Controller (ORC) and are connected to the vehicle
electrical system through the body wire harness.
The seat belt tensioners cannot be repaired and, if
faulty or damaged, the entire front seat belt buckle
must be replaced. The seat belt tensioners are not
intended for reuse and must be replaced following
any front airbag deployment.
OPERATION
WARNING: When the front airbag is deployed, the
tensioner will have deployed also and should be
replaced. Failure to do so could result in occupant
personal injury or death.
The seat belt tensioners are deployed by a signal
generated by the Occupant Restraint Controller
(ORC) through the driver or passenger seat belt ten-
sioner line 1 and line 2 (or squib) circuits. When the
ORC sends the proper electrical signal to the tension-
ers, the electrical energy generates enough heat to
initiate a small pyrotechnic gas generator.
Removing excess slack from the front seat belts not
only keeps the occupants properly positioned for an
airbag deployment following a frontal impact of the
vehicle, but also helps to reduce injuries that the
occupants of the front seat might experience in these
situations as a result of a harmful contact with the
steering wheel, steering column, instrument panel
and/or windshield.
The ORC monitors the condition of the seat belt
tensioners through circuit resistance, and will illumi-
nate the airbag indicator in the ElectroMechanical
Instrument Cluster (EMIC) and store a Diagnostic
Trouble Code (DTC) for any fault that is detected.
For proper diagnosis of the seat belt tensioners, use a
scan tool and the appropriate diagnostic information.
SEAT WEIGHT BLADDER &
PRESSURE SENSOR
DESCRIPTION
Vehicles equipped with the Occupant Classification
System (OCS) have a seat weight bladder and pres-
sure sensor unit (Fig. 54) that is integral to the pas-
senger front seat cushion. The bladder is sandwiched
between the seat cushion pan and seat cushion foam.
The bladder consists of two rectangular sheets of
an elastomeric material and a molded plastic elbow
fitting. The two sheets of material are sealed
together around their perimeter and heat staked to
each other at numerous regular points within their
field. The elbow fitting is sealed to a small round
hole in the lower surface of the bladder and is
pointed downward where it passes through a clear-
ance hole in the insulator pad and extends to just
below the seat cushion. The bladder is then filled
with a silicone fluid to become a pliable, quilted
membrane.
Under the seat cushion a short tube is securely
clamped at one end to the bladder nipple, and at the
other end to a nipple on the electronic pressure sen-
sor. The sensor housing features an integral mount
that snaps over a tab integral to the stamped steel
Occupant Classification Module (OCM) mounting
bracket welded to the underside of the passenger
front seat cushion frame.
Fig. 54 SEAT WEIGHT BLADDER AND PRESSURE
SENSOR - TYPICAL
1 - FASTENER (2)
2 - BLADDER
3-PAD
4 - TUBE
5 - PRESSURE SENSOR
RSRESTRAINTS8O-43

OPERATION
The PCM on NGC vehicles first senses that the
speed control is set. If the set speed is exceeded by
more than 4 mph (6.5 km/hr) and the throttle is
closed, the PCM on NGC vehicles causes the trans-
axle to downshift to THIRD gear. After downshifting,
the automatic speed control resumes normal opera-
tion. To ensure that an upshift is appropriate after
the set speed is reached, the PCM on NGC vehicles
waits until the speed control system opens the throt-
tle at least 6 degrees before upshifting to OVER-
DRIVE again.
If the driver applies the brakes, canceling auto-
matic speed control operation with the transaxle still
in THIRD gear, the PCM on NGC vehicles maintains
this gear until the driver opens the throttle at least 6
degrees to avoid an inappropriate upshift. The
upshift is also delayed for 2.5 seconds after reaching
the 6 degrees throttle opening in anticipation that
the driver might open the throttle enough to require
THIRD gear. This will avoid unnecessary and dis-
turbing transmission cycling. If the automatic speed
control RESUME feature is used after braking, the
upshift is delayed until the set speed is achieved to
reduce cycling and provide better response.
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 the Instru-
ment Cluster for speedometer diagnosis.
If a road test verifies an inoperative system, and
the speedometer operates properly, check for:
²A Diagnostic Trouble Code (DTC). If a DTC
exists, conduct tests per the Powertrain Diagnostic
Procedures manual.
²A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
²Loose or corroded electrical connections 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 at both ends of the speed
control servo cable.
²Smooth operation of throttle linkage and throttle
body air valve.
²Conduct electrical test at PCM.
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.
SPECIFICATIONS - TORQUE
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Servo Mounting Bracket
Nuts14 10.3 123.9
Servo Mounting Bracket
Bolts14 10.3 123.9
Servo Mounting Nuts 6.7 60
RSSPEED CONTROL8P-3
SPEED CONTROL (Continued)

VEHICLE THEFT SECURITY
TABLE OF CONTENTS
page page
VEHICLE THEFT SECURITY
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - SENTRY KEY
REMOTE ENTRY SYSTEM...............3
DIAGNOSIS AND TESTING - VEHICLE
THEFT SECURITY SYSTEM..............3
HOOD AJAR SWITCH - EXPORT
REMOVAL.............................3
INSTALLATION..........................3
SENTRY KEY REMOTE ENTRY MODULE
DESCRIPTION..........................3OPERATION............................4
DIAGNOSIS AND TESTING - SENTRY KEY
REMOTE ENTRY MODULE...............5
REMOVAL.............................6
INSTALLATION..........................6
TRANSPONDER KEY
DESCRIPTION..........................6
OPERATION............................6
STANDARD PROCEDURE - TRANSPONDER
PROGRAMMING.......................6
VTSS/SKIS INDICATOR LAMP
DESCRIPTION..........................8
OPERATION............................8
VEHICLE THEFT SECURITY
DESCRIPTION
VEHICLE THEFT SECURITY SYSTEM
The Vehicle Theft Security System (VTSS) is
designed to protect against whole vehicle theft. The
system monitors vehicle doors, and ignition action for
unauthorized operation (hood and liftgate for RG -
Export). The alarm activates:
²Sounding of the horn
²Flashing of the headlamps/park/tail lamps
²Flashing of the headlamps
²An engine kill feature (with SKREES)
SENTRY KEY REMOTE ENTRY SYSTEM
The Sentry Key Remote Entry System (SKREES)
is available as a factory-installed option on this vehi-
cle. It is designed to provide passive protection
against unauthorized vehicle use by disabling the
engine, after two (2) seconds of running, whenever an
invalid key is used to start the vehicle. The SKIS is
active whenever the ignition is on and does not
require any customer intervention. The primary com-
ponents of the system are the Sentry Key Remote
Entry Module (SKREEM), Sentry Key (integrated
key with tranponder and RKE on a circuit board),
indicator light, Body Control Module (BCM), and the
Powertrain Control Module (PCM). The SKREEM is
mounted to the steering column with the molded,
integral antenna mounted on the ignition housing.
The indicator light, is located in the Mechanical
Instrument Cluster (MIC).
OPERATION
VEHICLE THEFT SECURITY SYSTEM
Upon failure of proper Sentry Key Remote Entry
Module (SKREEM) communication to the PCM, the
PCM will shut off fuel after two seconds of run time.
The engine will not re-crank on the key cycle that
the failure occurred, a full key down sequence must
be performed for the engine to crank again. After six
consecutive fuel shut-offs, the engine will no longer
crank on subsequent key cycles. The failure must be
corrected and a valid communication process between
the SKREEM and the PCM must occur for the
engine to crank and start again.
The electronics for the VTSS are part of the Body
Control Module (BCM). The system is armed when
the vehicle is locked using the:
²Power door lock switches (with any door ajar)
²Remote Keyless Entry integrated key.
²Door Cylinder Lock Switches (RG only).
For vehicles equipped with Sentry Key Remote
Entry System (SKREES), the doors do not have to be
locked to enable the fuel shut off feature.
After the vehicle is locked and the last door is
closed, the set LED indicator in the Mechanical
Instrument Cluster (MIC) will flash quickly for 16
seconds, indicating that arming is in progress. If no
monitored systems are activated during this period,
the system will arm. The LED will extinguish unless
the liftgate is open. If the liftgate is open, the LED
will flash at a slower rate. This indicates that the
system is armed.
RSVEHICLE THEFT SECURITY8Q-1

RG Only- If fault is detected on the driver key
cylinder input, the indicator LED will remain solid
during the arming process, although the system will
still arm.
If the indicator LED does not illuminate at all
upon door closing it indicates that the system is not
arming.
Passive disarming occurs upon normal vehicle
entry by unlocking either door with the remote trans-
mitter (RG - ignition key or remote transmitter). This
disarming will also halt the alarm once it has been
activated.
A tamper alert exists to notify the driver that the
VTSS had been activated. This alert consists of 3
horn pulses when the vehicle is disarmed.
NOTE: The VTSS will not arm by pushing down the
door lock mechanism. This will manually override
the system.
RG Only- For Door Cylinder Lock Switch
Removal and Installation, refer to Electrical, Power
Locks, Door Cylinder Lock Switch.
If the VTSS is triggered, the horn will pulse, head-
lamps/marker lamps will flash, and the VTSS warn-
ing lamp will flash. If BCM determines the threat to
be false and the VTSS is not triggered again, the sys-
tem will shut down and rearm itself after three min-
utes. If a trigger is still active, the alarm will
continue for an additional 15 minutes without the
horn. The VTSS monitors the passenger compart-
ment (for RG - Export it also monitors the engine
compartment. If a malfunction occurs in the engine
compartment, the passenger compartment would still
arm and function normally).
NOTE: System will not arm if passenger compart-
ment is not secure.
NOTE: (RG - Export - If hood is not secure during
the arming sequence, the lamp will stay lit and not
flash. The system will arm with hood not secured
and the liftgate open).
ARMING THE VTSS - METHOD A
(1) With the key removed from the ignition lock
and any door open (excluding liftgate), actuate one of
the following:
²Power door lock button to LOCK,
²Key fob LOCK button
²Driver door lock key cylinder to locked position
(RG Only).
(2) Close all opened doors. Liftgate can remain
open.(3) After the last door is closed, an arming time-
out period of sixteen seconds will start, then the
VTSS will become armed.
ARMING THE VTSS - METHOD B
Actuating the key fob transmitter LOCK button,
key locking the front doors with the doors closed and
the ignition locked will begin the arming time-out
period. If method A, 16 second time-out sequence was
in process when method B was actuated, the 16 sec-
ond time-out will restart from the time of the second
actuation.
If the security lamp does not illuminate at all upon
final door closure, it indicates that the system is not
arming.
The current VTSS status armed or disarmed shall
be maintained in memory to prevent battery discon-
nects from disarming the system.
TRIGGERING THE VTSS
After the VTSS is armed, the following actions will
trigger the alarm:
²Opening any door (liftgate - only if opening via
liftgate button on key fob).
²Opening the hood (RG - Export)
²Turning the ignition to the RUN position.
NOTE: When the VTSS is ARMED, the interior
power door lock switch ªUNLOCKº will be disabled
until the vehicle is disarmed.
CAUTION: The VTSS indicator LED will trigger and
engine will continue to run if the vehicle is
equipped with SKREES and the proper key is used
to start the vehicle. This condition will occur if the
VTSS has been triggered. If valid key is used, VTSS
will disarm
SENTRY KEY REMOTE ENTRY SYSTEM
The SKREES includes keys from the factory which
are pre-programmed. Each SKREEM will recognize a
maximum of eight Sentry Keys. If the customer
would like to own additional keys other than those
provided with the vehicle, they can be purchased
from any authorized dealer. These keys must be pro-
grammed to the SKREEM on the vehicle in order for
the system to recognize them as valid keys. This can
be done by the dealer with a DRBllltscan tool or by
a customer if this feature is available in their market
and they have two (2) valid keys already available to
them. Refer to the Service Procedures portion of this
system for additional details. The SKREES performs
a self-test each time the ignition switch is turned to
the ON position and will store Diagnostic Trouble
Codes (DTC's) if a system malfunction is detected.
8Q - 2 VEHICLE THEFT SECURITYRS
VEHICLE THEFT SECURITY (Continued)

The SKREES can be diagnosed and any stored DTC's
can be retrieved using a DRBllltscan tool as
described in the appropriate Body Diagnostic Proce-
dures information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - SENTRY KEY
REMOTE ENTRY SYSTEM
WARNING: On vehicles equipped with airbags, refer
to electrical, restraints, warnings, before attempting
component diagnosis or service. Failure to take the
proper precautions could result in accidental airbag
deployment and possible personal injury or death.
NOTE: The following tests may not prove conclu-
sive in the diagnosis of this system. The most reli-
able, efficient, and accurate means to diagnose the
Sentry Key Remote Entry System (SKREES)
involves the use of a DRBIIITscan tool. Refer to the
proper Body Diagnostic Procedures information.
The Sentry Key Remote Entry System (SKREES)
and the Programmable Communication Interface
(PCI) bus network should be diagnosed using a scan
tool. The scan tool will allow confirmation that the
PCI bus is functional, that the Sentry Key Remote
Entry Module (SKREEM) is placing the proper mes-
sages on the PCI bus, and that the Powertrain Con-
trol Module (PCM) is receiving the PCI bus
messages. Refer to the proper Body Diagnostic Proce-
dures information, and Wiring Diagrams for complete
circuit descriptions and diagrams.
(1) Check the fuses in the Integrated Power Mod-
ule (IPM). If OK, go to Step 2. If not OK, repair the
shorted circuit or component as required and replace
the faulty fuse.
(2) Disconnect and isolate the battery negative
remote cable from the remote terminal. Unplug the
wire harness connector at the SKREEM. Check for
continuity between the ground circuit cavity of the
SKREEM wire harness connector and a good ground.
There should be continuity. If OK, go to Step 3. If not
OK, repair the open circuit to ground as required.
(3) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
SKREEM wire harness connector. If OK, go to Step
4. If not OK, repair the open circuit to the fuse in the
IPM as required.
(4) Turn the ignition switch to the ON position.
Check for battery voltage at the fused ignition switch
output (run/start) circuit cavity of the SKREEM wire
harness connector. If OK, use a scan tool and the
proper Body Diagnostic Procedures information tocomplete the diagnosis of the SKREES. If not OK,
repair the open circuit to the fuse in the IPM as
required.
DIAGNOSIS AND TESTING - VEHICLE THEFT
SECURITY SYSTEM
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 har-
ness connectors, splices and grounds. Using a
DRBIIItscan tool. Refer to the proper Body Diagnos-
tic Procedures information for test procedures.
HOOD AJAR SWITCH -
EXPORT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Using a small flat blade screwdriver, pry trig-
ger switch from the bracket on the left fender well.
(3) Disconnect the hood ajar switch from the wire
connector and remove from vehicle.
INSTALLATION
(1) Connect the hood ajar switch to the wire conec-
tor.
(2) Press the hood ajar switch into position on the
bracket located on the left inner fender well.
(3) Reconnect the battery negative cable.
(4) Close the hood and check for proper operation.
SENTRY KEY REMOTE ENTRY
MODULE
DESCRIPTION
The Sentry Key Remote Entry Module (SKREEM)
performs the functions of the Sentry Key Immobilizer
Module (SKIM), Remote Keyless Entry (RKE) Mod-
ule, and the Tire Pressure Monitoring (TPM) System
(previously part of the Electronic Vehicle Information
Center (EVIC).
The SKREEM is located in the same location as
the SKIM was and is mounted the same way. It looks
identical, but has added capabilities.
SENTRY KEY IMMOBILIZER
The Sentry Key Immobilizer System (SKIS)
authenticates an electronically coded Transponder
Key placed into the ignition and sends a valid/invalid
key message to the Powertrain Control Module
RSVEHICLE THEFT SECURITY8Q-3
VEHICLE THEFT SECURITY (Continued)

(PCM) based upon the results. The ªVALID/INVALID
KEYº message communication is performed using a
rolling code algorithm via the Programmable Com-
munication Interface (PCI) data bus. A ªVALID KEYº
message must be sent to the Powertrain Control
Module (PCM) within two seconds of ignition ON to
free the engine from immobilization.
The SKREEM contains a Radio Frequency (RF)
transceiver and a microprocessor. The SKREEM
retains in memory the ID numbers of any Sentry Key
that is programmed to it. The maximum number of
keys that may be programmed to each module is
eight (8). The SKREEM also communicates over the
Programmable Communication Interface (PCI) data
bus with the Powertrain Control Module (PCM), the
Body Control Module (BCM), the Mechanical Instru-
ment Cluster (MIC), and the DRB IIItscan tool. The
SKREEM transmits and receives RF signals through
a tuned antenna enclosed within a molded plastic
ring formation that is integral to the SKREEM hous-
ing. When the SKREEM is properly installed on the
steering column, the antenna ring fits snugly around
the circumference of the ignition lock cylinder hous-
ing. If this ring is not mounted properly, communica-
tion problems may arise in the form of transponder-
related faults.
For added system security, each SKREEM is pro-
grammed with a unique9Secret Key9code. This code
is stored in memory and is sent over the PCI bus to
the PCM and to each key that is programmed to
work with the vehicle. The9Secret Key9code is there-
fore a common element found in all components of
the Sentry Key Immobilizer System (SKIS). In the
event that a SKREEM replacement is required, the
9Secret Key9code can be restored from the PCM by
following the SKIM replacement procedure found in
the DRB IIItscan tool. Proper completion of this
task will allow the existing ignition keys to be repro-
grammed. Therefore, new keys will NOT be needed.
In the event that the original9Secret Key9code can
not be recovered, new ignition keys will be required.
The DRB IIItscan tool will alert the technician if
key replacement is necessary. Another security code,
called a PIN, is used to gain secured access to the
SKREEM for service. The SKREEM also stores in its
memory the Vehicle Identification Number (VIN),
which it learns through a bus message from the
assembly plant tester. The SKIS scrambles the infor-
mation that is communicated between its components
in order to reduce the possibility of unauthorized
SKREEM access and/or disabling.
REMOTE KEYLESS ENTRY (RKE)
The RKE transmitter uses radio frequency signals
to communicate with the SKREEM. The SKREEM is
on the PCI bus. When the operator presses a buttonon the transmitter, it sends a specific request to the
SKREEM. In turn the SKREEM sends the appropri-
ate request over the PCI Bus to the:
²Body Control Module (BCM) to control the door
lock and unlock functions, the liftgate lock and
unlock functions, the arming and disarming of the
Vehicle Theft Security System (VTSS) (if equipped),
and the activation of illuminated entry.
²Integrated Power Module (IPM) to activate the
park lamps, the headlamps, and the horn for horn
chirp. If requested, the BCM sends a request over
the PCI Bus to the:
TIRE PRESSURE MONITORING (TPM)
If equipped with the Tire Pressure Monitoring
(TPM) System, each of the vehicles four wheels will
have a valve stem with a pressure sensor and radio
transmitter built in. Signals from the tire pressure
sensor/transmitter are received and interpreted by
the SKREEM.
A sensor/transmitter in a mounted wheel will
broadcast its detected pressure once per minute
when the vehicle is moving faster than 15 mph (24
km/h). Each sensor/transmitter's broadcast is
uniquely coded so that the SKREEM can determine
the location.
OPERATION
SENTRY KEY IMMOBILIZER
The Sentry Key Remote Entry Module (SKREEM)
receives an encrypted Radio Frequency (RF) signal
from the transponder key. The SKREEM then
decrypts the signal and broadcasts the requested
remote commands to the appropriate modules in the
vehicle over the Programmable Communication
Interface (PCI) data bus. A valid transponder key ID
must be incorporated into the RF signal in order for
the SKREEM to pass the message on to the appro-
priate modules.
Automatic transponder key synchronization is done
by the SKREEM if a valid transponder key is
inserted into the ignition cylinder, and the ignition is
turned ON. This provides a maximum operation win-
dow for RKE functions.
Each Sentry Key Remote Entry System (SKREES)
consists of a SKREEM and a transponder key. Each
system has a secret key code unique to that system.
The secret key is electronically coded in the
SKREEM and in all programmed transponder keys.
It is used for immobilization and RKE functions for
data security. In addition, each transponder key will
have a unique identification. For North America, the
options are a 3-button or 6 button integrated keys.
For Export, the options are 2-button or 5 button key
fobs. (Export does not get the integrated key).
8Q - 4 VEHICLE THEFT SECURITYRS
SENTRY KEY REMOTE ENTRY MODULE (Continued)