ECU DODGE NEON 2000 Service Workshop Manual

The fusible link, fuses and relays are available for
service replacement. The PDC unit cannot be
repaired and is only serviced as a unit with the
engine compartment wire harness. If the PDC is
faulty or damaged, the engine compartment wire har-
ness assembly must be replaced.
FUSE BLOCK
An electrical Fuse Block is located in the left end
of the instrument panel (Fig. 2). It serves to simplify
and centralize numerous electrical components, as
well as to distribute electrical current to many of the
accessory systems in the vehicle.
The Fuse Block is positioned on a mounting
bracket up and under the left instrument panel. It is
secured by two screws. The fuse block is concealed
behind the left instrument panel end cap. The left
end cap is a snap-fit access cover that conceals the
fuse block fuses. A fuse layout placard is on the back
of the end cap to ensure proper fuse identification.
The fuse block houses blade-type fuses and auto-
matic resetting circuit breakers (Fig. 3). Internal con-
nection of all the fuse block circuits is accomplished
by an intricate network of hard wiring and bus bars.
Refer toJunction Blockin the Component Index of
Group 8W - Wiring Diagrams for complete circuit
diagrams.
The fuses and circuit breakers are available for
service replacement. The fuse block unit cannot be
repaired and is only serviced as an assembly. If any
circuit or the fuse block housing is faulty or dam-
aged, the entire fuse block and instrument panel
wire harness assembly must be replaced.
REMOVAL AND INSTALLATION
FUSE BLOCK
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANYSTEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
REMOVAL
The Fuse Block is serviced with the instrument
panel wire harness. If service is required to the fuse
block, the entire instrument panel harness must be
replaced.
(1) The instrument panel must be removed from
the vehicle. Refer to Group 8E-Instrument Panel and
Systems for Instrument Panel Removal and Installa-
tion.
(2) With the instrument panel on the bench,
de-trim the instrument panel enough to gain access
to all screws and connectors to remove instrument
panel wire harness with fuse block.
INSTALLATION
For installation, reverse the above procedures.
Ensure that the wire terminals and connectors are in
good condition and connectors are properly installed.
POWER DISTRIBUTION CENTER (PDC)
The Power Distribution Center (PDC) is serviced
as a unit with the engine compartment wire harness.
If any internal circuit of the PDC or the PDC hous-
ing is faulty or damaged, the entire PDC and engine
compartment wire harness unit must be replaced.
Fig. 2 Fuse Block Location
Fig. 3 Fuse Block
1 ± CIRCUIT BREAKER 2
2 ± CIRCUIT BREAKER 1
8O - 2 POWER DISTRIBUTION SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

REMOVAL
(1) Disconnect and isolate the battery negative
cable (Fig. 4).
(2) Disconnect each of the engine compartment
wire harness connectors. Refer to8W-90 - Connec-
tor Locationsin Group 8W - Wiring Diagrams for
more information on the locations of the affected con-
nectors.
(3) Remove the fasteners that secure each of the
engine compartment wire harness ground eyelets to
the vehicle body and chassis components. Refer to
8W-90 - Connector Locationsin Group 8W - Wir-
ing Diagrams for more information on the ground
eyelet locations.
(4) Disengage each of the retainers that secure the
engine compartment wire harness to the vehicle body
and chassis components. Refer to8W-90 - Connec-tor Locationsin Group 8W - Wiring Diagrams for
more information on the retainer locations.
(5) Remove the one screw and disengage the PDC
housing from the left inner fender well.
(6) Remove the PDC and the engine compartment
wire harness from the engine compartment as a unit.
INSTALLATION
NOTE: If the power distribution center (PDC) is
being replaced with a new unit, be certain to trans-
fer each of the fuses and relays from the old power
distribution center to the proper cavities of the new
power distribution center. Refer to Power Distribu-
tion in Group 8W - Wiring Diagrams for the proper
power distribution center cavity assignments.
(1) Position the PDC in the engine compartment.
(2) Align the PDC mounting pin with the inner
fender well hole.
(3) Place PDC down in engine compartment and
install retaining screw.
(4) Route the engine compartment wire harness
from the PDC through the engine compartment,
engaging each of the harness retainers to the mount-
ing provisions in the vehicle body and chassis compo-
nents. Refer to8W-90 - Connector Locationsin
Group 8W - Wiring Diagrams for more information
on the harness routing and retainer locations.
(5) Install and tighten the fasteners that secure
each of the engine compartment wire harness ground
eyelets to the vehicle body and chassis components.
Refer to8W-90 - Connector Locationsin Group
8W - Wiring Diagrams for more information on the
ground eyelet locations.
(6) Reconnect each of the engine compartment
wire harness connectors. Refer to8W-90 - Connec-
tor Locationsin Group 8W - Wiring Diagrams for
more information on the locations of the affected con-
nectors.
(7) Torque nut retaining positive battery cable at
PDC to 96 - 141 Nzm (85 - 130 in. lbs.).
(8) Reconnect the battery negative cable.
Fig. 4 Battery Negative Cable Remove/Install
1 ± NEGATIVE CABLE
2 ± NEGATIVE BATTERY POST
PLPOWER DISTRIBUTION SYSTEMS 8O - 3
REMOVAL AND INSTALLATION (Continued)

POWER LOCK SYSTEMS
TABLE OF CONTENTS
page page
POWER DOOR LOCKS...................... 1REMOTE KEYLESS ENTRY (RKE).............. 4
POWER DOOR LOCKS
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
INTRODUCTION..........................1
POWER DOOR LOCKS.....................2
CHILD PROTECTION LOCKS................2
DOOR LOCK INHIBIT.......................2
DIAGNOSIS AND TESTING
DOOR LOCK MOTOR......................2
DOOR LOCK SWITCH......................2SERVICE PROCEDURES
DOUBLE ACTIVATION UNLOCK...............3
ROLLING DOOR LOCKS....................3
REMOVAL AND INSTALLATION
DOOR LOCK MOTOR/LATCH.................3
DOOR LOCK SWITCH......................3
REMOTE KEYLESS ENTRY (RKE) MODULE.....3
DESCRIPTION AND OPERATION
INTRODUCTION
All doors can be locked or unlocked electrically by
operating the switch on either front door panel.
When the door lock switch is activated the Remote
Keyless Entry Module provides power to the door
lock motors through relays internal to the module.
The Remote Keyless Entry (RKE) Module also con-
trols the Vehicle Theft Security System (VTSS).
All doors can be locked or unlocked mechanically
and independently with their respective locking
knobs. The front doors can also be unlocked by actu-
ation of the inside remote door handle.
The RKE Module has three modes of operation
including customer usage mode, dealer lot storage
mode, and shipping mode. The customer usage mode
provides full functionality of the module and is the
mode in which the RKE module should be operating
when used by the customer. Dealer lot storage mode
and shipping modes are reduced power modes meant
to extend vehicle battery life during shipping and
storage in the dealer lot. Dealer lot storage mode pro-
vides limited VTSS and power door lock functions,
but disables the Remote Keyless Entry (RKE) func-
tions. This mode is intended to be used when the
vehicle is on the dealer lot to provide VTSS coverageof the vehicle while minimizing battery drain. Ship-
ping mode disables all normal functions (i.e. power
door locks, RKE, and VTSS) of the module, and is
intended to be used when the vehicle is shipped from
the assembly plant.
NOTE: The dealer must remove the module from
ªShip Modeº and place the RKE Module into either
the ªDealer Lotº storage or ªCustomer Usageº
modes of operation after receiving the vehicle from
the assembly plant. Refer to Group 8Q-Vehicle
Theft/Security Systems, Switching Operating
Modes/Configuring a New Module under Service
Procedures.
CENTRAL LOCKING/UNLOCKING
The door locks can be locked or unlocked electri-
cally via the exterior door key cylinders to provide
the central locking/unlocking feature. The central
locking/unlocking feature incorporates a customer
programmable ``Double activation unlockº feature
which operates in the following manner: When
enabled, the first turn of the key cylinder to the
UNLOCK position (toward the front of the vehicle)
will mechanically unlock the door whose key cylinder
is being turned. A second turn of the key cylinder to
the UNLOCK position (within five seconds of the
PLPOWER LOCK SYSTEMS 8P - 1

first turn) will cause all vehicle doors to unlock elec-
trically. When this feature is disabled, all vehicle
doors will be unlocked electrically upon the first turn
of a key cylinder to the UNLOCK position. The vehi-
cle is locked electrically by turning the key cylinder
to the LOCK position once, regardless of the state of
the double activation unlock feature.
POWER DOOR LOCKS
The Remote Keyless Entry (RKE) Module actuates
the power door lock relays when a door lock switch is
activated. If the door lock switch is pressed for longer
than eight consecutive seconds, the RKE module will
de-energize the door lock motors.
The system includes the rolling door locking fea-
ture. The vehicle is shipped with the system enabled.
When the system is disabled the door locks will work
by use of the door lock switches and the Remote Key-
less Entry system only. When the rolling door lock
system is enabled, the RKE module will automati-
cally lock all the vehicle doors when all of the follow-
ing conditions are met:
²All doors are closed
²The vehicle speed exceeds 15 +/- 1 mph.
²The throttle position sensor tip-in is greater
than 10 +/- 2 degrees.
The RKE module will automatically re-lock all
doors if the above conditions are met and if any of
the doors become ajar and then closed again.
The enabling/disabling of the rolling door lock fea-
ture is customer programmable, as well as program-
mable with the DRB IIItscan tool.
The power lock motors are also equipped with a
thermal protection system which prevents the motors
from burning out. The motors may chatter if they are
continuously activated.
CHILD PROTECTION LOCKS
The child protection locks are on the rear doors
only. The lock, when engaged, will disable the inside
door handle from opening the door. The lock is part
of the latch/lock assembly. The lock is engaged by
moving a lever that is located on the rearward inside
edge of the door.
DOOR LOCK INHIBIT
With the key in the ignition switch and the driver
door open, the Remote Keyless Entry (RKE) Modulewill ignore the command to lock the power door locks
via the interior driver door lock switch. Once the key
is removed, or the driver door is closed, the RKE
module will allow the power door locks to lock via the
interior door lock switches.
DIAGNOSIS AND TESTING
DOOR LOCK MOTOR
(1) Make certain battery is in normal condition
and fuses powering the RKE module aren't blown
before circuits are tested.
(2) To determine which motor is faulty, check each
individual door for electrical lock and unlock or dis-
connect the motor connectors one at a time, while
operating the door lock switch.
(3) In the event that none of the motors work, the
problem maybe caused by a shorted motor, a bad
switch or a bad relay internal to the RKE module.
Disconnecting a defective motor will allow the others
to work.
(4) To test an individual door lock motor, discon-
nect the electrical connector from the motor.
(5) To lock the door, connect a 12 volt power source
to one pin of the lock motor and a ground wire to the
other pin.
(6) To unlock the door, reverse the wire connec-
tions at the motor pin terminals.
(7) If these results are NOT obtained, replace the
motor.
DOOR LOCK SWITCH
(1) Remove the switch from its mounting location,
and disconnect from vehicle wiring harness. Refer to
Door Lock Switch Removal and Installation in this
section.
(2) Using an ohmmeter, refer to Door Lock Switch
Resistance Test table to determine if switch resis-
tance is correct in the Lock and Unlock switch posi-
tions. Refer to Group 8W-Wiring Diagrams for
harness connector pin-outs.
DOOR LOCK SWITCH RESISTANCE
SWITCH POSITION CONTINUITY BETWEEN RESISTANCE VALUE
LOCK 2 AND 3 1000V
UNLOCK 2 AND 3 249V
8P - 2 POWER LOCK SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

NOTE: The dealer must remove the module from
ªShip Modeº and place the RKE Module into either
the ªDealer Lotº storage or ªCustomer Usageº
modes of operation after receiving the vehicle from
the assembly plant. Refer to Group 8Q-Vehicle
Theft/Security Systems, Switching Operating
Modes/Configuring a New Module under Service
Procedures.
REMOTE KEYLESS ENTRY SYSTEM
The system allows locking and unlock of vehicle
door(s) and deck lid by remote control using a hand
held radio frequency (RF) transmitter. The vehicle
speed must be less than five miles per hour before
the deck lid can be unlatched with the transmitter.
The receiver may receive signals from four transmit-
ters. Each transmitter has its own code and the code
has been stored in memory. If the transmitter is
replaced or other transmitters are added, the code for
each unit must be learned.
REMOTE KEYLESS ENTRY TRANSMITTER
The transmitter has four buttons for operation
(Fig. 1). They are LOCK, UNLOCK, DECK LID
RELEASE, and PANIC.
²The UNLOCK button will unlock the driver door
and enable illuminated entry. Pushing and releasing
the button once will unlock the driver door. Pushing
and releasing the button two times within a five sec-
ond period will unlock all doors (double unlock acti-
vation enabled).
²Upon pressing the LOCK button, the horn will
sound a short chirp (if enabled) and flash the park
lamps to notify that the all door lock signal was
received and acted upon. Illuminated entry is can-
celled and the interior lamps are faded to off.
²Pushing and releasing the DECK LID
RELEASE button twice within a five second period
will actuate the decklid release solenoid, causing the
deck lid to be slightly ajar. If so desired, the decklid
may be set to release after one button push by the
dealer. For procedures on programming with the
DRB IIItscan tool, refer to the proper Body Diagnos-
tic Procedures Manual.
²Pushing the PANIC button will cause the panic
alarm to sound for three minutes, until the panic
button is pressed a second time, or until the vehicle
reaches a speed of 15 mph.
HORN CHIRP TOGGLE
Once the transmitters have been programmed, the
horn chirp can be enabled/disabled by sending the
horn chirp toggle operation code to the RKE Module.
This can be done using a DRB IIItscan tool or by
the customer. The horn chirp will enter the oppositestate of its current programmed state by receiving
this operation code. The RKE module is responsible
for keeping track of the horn chirp status.
DIAGNOSIS AND TESTING
REMOTE KEYLESS ENTRY MODULE
For procedures on diagnosing and testing the RKE
Module's RKE functions, refer to the proper Body
Diagnostic Procedures Manual.
DECKLID RELEASE SOLENOID
(1) Confirm operation of RKE transmitter(s) by
actuating Lock and Unlock functions.
(2) Confirm lead is connected to deck lid release
solenoid.
(3) Unplug lead, and use an ohmmeter to verify
continuity of connection between pin 2 of the harness
connector and ground. Refer to Group 8W-Wiring
Diagrams for Connector Pin-Outs.
(4) Connect test light to pin 1 of the harness con-
nector and actuate decklid release button on trans-
mitter. Refer to Group 8W-Wiring Diagrams for
Connector Pin-Outs.
(5) If test light comes on, the wiring circuit
between the RKE module and the solenoid is func-
tional, and the decklid solenoid should be replaced.
(6) If test light does not come on, refer to the
proper Body Diagnostic Procedures Manual for fur-
ther troubleshooting information.
SERVICE PROCEDURES
HORN CHIRP TOGGLE
The toggling of the horn chirp (between enabled
and disabled) can be performed with the use of the
DRB IIItscan tool or by the customer.
DRB lllTPROGRAMMING
When using the DRB IIItscan tool, select:
(1) ªTheft Alarmº
(2) ªVTSSº
(3) ªMiscellaneousº
and then the desired function.
CUSTOMER PROGRAMMING
Using a transmitter programmed to the RKE Mod-
ule, the status of the horn chirp may be toggled by
the customer.
NOTE: The RKE Module is responsible for keeping
track of the horn chirp status; thus this procedure
does not need to be repeated for each transmitter
programmed to the system.
PLPOWER LOCK SYSTEMS 8P - 5
DESCRIPTION AND OPERATION (Continued)

(1) With the ignition switch in RUN position, press
and hold the transmitter Unlock button (Fig. 1) for a
minimum of 4 seconds to a maximum of 10 seconds.
(2) Within the 4-10 second range, depress the
transmitter Lock button (Fig. 1). A chime will be
heard to indicate a successful toggle, at which time
the buttons may be released.
SWITCHING OPERATING MODES/
CONFIGURING A NEW MODULE
Refer to Group 8Q-Vehicle Theft/Security Systems,
Switching Operating Modes/Configuring A New Mod-
ule under Service Procedures.
TRANSMITTER PROGRAMMING
The Remote Keyless Entry transmitters can be
programmed with the use of the DRB IIItscan tool
or by the customer.
DRB lllTPROGRAMMING
When using the DRB IIItscan tool, select:
(1) ªTheft Alarmº
(2) ªVTSSº
(3) ªMiscellaneousº
and then the desired function.
CUSTOMER PROGRAMMING
For a customer to be able to program RKE trans-
mitters themselves, at least one RKE transmitter
must be programmed already. This procedure is to
add additional transmitters. If all transmitters are
lost, the DRB IIItscan tool must be used to program
the new transmitters.
(1) With the ignition switch in RUN position, press
and hold the transmitter Unlock button (Fig. 1) for a
minimum of 4 seconds to a maximum of 10 seconds.
(2) Within the 4-10 second range, depress the
transmitter Lock button (Fig. 1). A chime will be
heard to indicate successful toggle, at which time the
buttons may be released.
(3) Turn the ignition switch off to exist transmitter
programming mode.
REMOVAL AND INSTALLATION
DECK LID RELEASE SOLENOID
REMOVAL
(1) Disconnect and isolate the battery negative
cable (Fig. 2).
(2) Raise deck lid to the full up position.
(3) Unplug connector from solenoid.
(4) Remove two solenoid mounting screws.
(5) Remove solenoid from vehicle.
INSTALLATION
For installation, reverse the above procedures.
Adjust the deck lid latch and striker so that the deck
lid latches with a moderate slam, and so that the
deck lid releases properly whenever the power deck
lid release is activated.
REMOTE KEYLESS ENTRY MODULE
REMOVAL
(1) Disconnect and isolate the battery negative
cable (Fig. 2).
(2) Remove the instrument panel top cover. Refer
to Group 8E-Instrument Panel and Systems, Instru-
ment Pane Top Cover Removal and Installation.
(3) Remove the two screws holding the RKE mod-
ule to the instrument panel assembly (Fig. 3).
(4) Slide locking tab of the wiring connector side-
ways to unlock tab, and remove connector from RKE
module.
(5) Remove RKE module from vehicle.
NOTE: When replacing a faulty RKE Module, the
replacement module must be configured with the
DRB lllTscan tool for proper operation. Refer to
Group 8Q-Vehicle Theft/Security Systems, Switch-
ing Operating Modes/Configuring a New Module
under Service Procedures. Additionally, all transmit-
ters must be reprogrammed to the new RKE mod-
ule.
Fig. 2 Battery Negative Cable Remove/Install
1 ± NEGATIVE CABLE
2 ± NEGATIVE BATTERY POST
8P - 6 POWER LOCK SYSTEMSPL
SERVICE PROCEDURES (Continued)

VEHICLE THEFT/SECURITY SYSTEM
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
INTRODUCTION..........................1
VEHICLE THEFT/SECURITY SYSTEM (VTSS)...1
SENTRY KEY IMMOBILIZER SYSTEM (SKIS)...2
SENTRY KEY IMMOBILIZER MODULE
(SKIM)................................2
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER.........................3
SENTRY KEY IMMOBILIZER SYSTEM
INDICATOR LAMP.......................4
TRIGGERING THE VTSS....................4
DIAGNOSIS AND TESTING
SENTRY KEY IMMOBILIZER SYSTEM.........4
VEHICLE THEFT/SECURITY SYSTEM (VTSS)...5SERVICE PROCEDURES
SENTRY KEY IMMOBILIZER SYSTEM
INITIALIZATION.........................5
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER PROGRAMMING...........5
SWITCHING OPERATING MODES/
CONFIGURING A NEW MODULE............6
REMOVAL AND INSTALLATION
DOOR CYLINDER LOCK SWITCH.............7
HOOD AJAR SWITCH......................7
SENTRY KEY IMMOBILIZER MODULE
(SKIM)................................7
VEHICLE THEFT/SECURITY SYSTEM DECK
LID SECURITY (KNOCK OUT) SWITCH.......8
DESCRIPTION AND OPERATION
INTRODUCTION
The Vehicle Theft/Security System (VTSS) is
designed to protect against whole vehicle theft. The
system monitors vehicle doors, hood, trunk key cylin-
der, and ignition for unauthorized operation.
The VTSS activates:
²Sounding of the horn.
²Flashing of the park lamps.
²Flashing of the headlamps.
The RKE Module has three modes of operation
including customer usage mode, dealer lot storage
mode, and shipping mode. The customer usage mode
provides full functionality of the module and is the
mode in which the RKE Module should be operating
when used by the customer. Dealer lot storage mode
and shipping mode are reduced power modes meant
to extend vehicle battery life during shipping and
storage in the dealer lot. Dealer lot storage mode pro-
vides limited VTSS and power door lock functions,
and disables the Remote Keyless Entry (RKE) func-
tions. This mode is intended to be used when the
vehicle is on the dealer lot to provide VTSS coverage
of the vehicle while minimizing battery drain. Ship-
ping mode disables all normal functions of the mod-
ule with the exception of communications over the
vehicle's PCI bus, and is intended to be used when
the vehicle is shipped from the assembly plant. The
dealer must remove the module from shipping modeand place it into either the dealer lot storage or cus-
tomer usage modes of operation.
NOTE: The dealer must remove the module from
ªShip Modeº and place the RKE Module into either
the ªDealer Lotº storage or ªCustomer Usageº
modes of operation after receiving the vehicle from
the assembly plant. Refer to Switching Operating
Modes/Configuring a New Module under Service
Procedures in this section.
VEHICLE THEFT/SECURITY SYSTEM (VTSS)
In the customer usage mode of operation, the sys-
tem is armed when the vehicle is locked using the:
²Power door lock switches.
²Remote Keyless Entry (RKE) transmitter.
After the vehicle is locked and the last door is
closed, the circular red VTSS indicator in the instru-
ment cluster will flash quickly for 16 seconds, indi-
cating that arming is in progress. If no monitored
systems are activated during this period (excluding
the hood and trunk key cylinder), the system will
arm. After 16 seconds, the LED will continue to flash
at a slower rate indicating the system is armed.
If the hood ajar switch and/or trunk key cylinder
switch(s) are not sensed by the system, the indicator
LED will remain lit during the arming process,
although the system will still arm. If the VTSS indi-
cator does not illuminate at all upon door closing it
indicates that the system is not arming.
PLVEHICLE THEFT/SECURITY SYSTEM 8Q - 1

VTSS disarming occurs upon normal vehicle entry
by unlocking either door via the key cylinders or
RKE transmitter, or by starting the vehicle with a
valid Sentry Key. This disarming will also halt the
alarm once it has been activated.
A tamper alert exists to notify the driver that the
system had been activated. This alert consists of 3
horn pulses when the vehicle is disarmed.
The VTSS will not arm by mechanically locking the
vehicle doors. This will manually override the sys-
tem.
In the dealer lot storage mode of operation, all of
the above descriptions of the VTSS are true with the
following exceptions:
²Remote Keyless Entry functions are disabled,
and cannot be used for arming/disarming the VTSS.
²The VTSS indicator is non-operational.
SENTRY KEY IMMOBILIZER SYSTEM (SKIS)
The Sentry Key Immobilizer System (SKIS) is
designed to provide passive protection against unau-
thorized vehicle use by preventing the engine from
operating while the system is armed. The primary
components of this system are the Sentry Key Immo-
bilizer Module (SKIM), the Sentry Key transponder,
the Vehicle Theft/Security System (VTSS) indicator
LED, and the Powertrain Control Module (PCM).
The SKIM is installed on the steering column near
the ignition lock cylinder. The transponder is located
under the molded rubber cap on the head of the igni-
tion key. The VTSS indicator LED is located in the
instrument cluster.
The SKIS includes three valid Sentry Key tran-
sponders from the factory, one being a valet key. This
is so the customer can self program new keys if one
is lost. If the customer wishes, additional non-coded
blank Sentry Keys are available. These blank keys
can be cut to match a valid ignition key, but the
engine will not start unless the key transponder is
also programmed to the vehicle. The SKIS will recog-
nize no more than eight valid Sentry Key transpon-
ders at any one time.
The SKIS performs a self-test each time the igni-
tion switch is turned to the ON position, and will
store Diagnostic Trouble Codes (DTC's) if a system
malfunction is detected. The SKIS can be diagnosed,
and any stored DTC can be retrieved using a DRB
llltscan tool as described in the proper Body Diag-
nostic Procedures Manual.
SENTRY KEY IMMOBILIZER MODULE (SKIM)
The Sentry Key Immobilizer Module (SKIM) (Fig.
1) contains a Radio Frequency (RF) transceiver and a
central processing unit, which includes the Sentry
Key Immobilizer System (SKIS) program logic. The
SKIS programming enables the SKIM to programand retain in memory the codes of at least two, but
no more than eight electronically coded Sentry Key
transponders. The SKIS programming also enables
the SKIM to communicate over the Programmable
Communication Interface (PCI) bus network with the
Powertrain Control Module (PCM), the instrument
cluster and/or the DRB IIItscan tool.
The SKIM transmits and receives RF signals
through a tuned antenna enclosed within a molded
plastic ring formation that is integral to the SKIM
housing. When the SKIM is properly installed on the
steering column, the antenna ring is oriented around
the circumference of the ignition lock cylinder hous-
ing (Fig. 1). This antenna ring must be located
within eight millimeters (0.31 inches) of the Sentry
Key in order to ensure proper RF communication
between the SKIM and the Sentry Key transponder.
For added system security, each SKIM is pro-
grammed with a unique ªSecret Keyº code and a
security code. The SKIM keeps the ªSecret Keyº code
in memory and sends the code over the CCD data
bus to the PCM, which also keeps this code in its
memory. The SKIM also sends the ªSecret Keyº code
to each of the programmed Smart Key transponders.
The security code is used by the assembly plant to
access the SKIS for initialization, or by the dealer
technician to access the system for service. The
SKIM also stores in its memory the Vehicle Identifi-
cation Number (VIN), which it learns through a PCI
bus message from the PCM during initialization.
The SKIM and the PCM both use software that
includes a rolling code algorithm strategy, which
helps to reduce the possibility of unauthorized SKIS
Fig. 1 Sentry Key Immobilizer Module (SKIM)
Location
1 ± STEERING COLUMN
2 ± SKIM ELECTRICAL CONNECTOR
3 ± SKIM
8Q - 2 VEHICLE THEFT/SECURITY SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM. However, the use of this strategy also means
that replacement of either the SKIM or the PCM
units will require a system initialization procedure to
restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM then sends a ªvalid keyº message to
the PCM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM. The PCM will enable or
disable engine operation based upon the status of the
SKIM messages.
The SKIM also sends messages to the instrument
cluster over the PCI bus network to control the VTSS
indicator LED. The SKIM sends messages to the
instrument cluster to turn the LED on for about
three seconds when the ignition switch is turned to
the ON position as a bulb test. After completion of
the bulb test, the SKIM sends bus messages to keep
the LED off for a duration of about one second. Then
the SKIM sends messages to turn the LED on or off
based upon the results of the SKIS self-tests. If the
VTSS indicator LED comes on and stays on after the
bulb test, it indicates that the SKIM has detected a
system malfunction and/or that the SKIS has become
inoperative.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to the instrument cluster to flash the VTSS
indicator LED. The SKIM can also send messages to
the instrument cluster to flash the LED and to gen-
erate a single audible chime tone. These functions
serve as an indication to the customer that the SKIS
has been placed in its ªCustomer Learnº program-
ming mode. See Sentry Key Immobilizer System
Transponder Programming in this group for more
information on the ªCustomer Learnº programming
mode.
For diagnosis or initialization of the SKIM and the
PCM, a DRB IIItscan tool and the proper Body
Diagnostic Procedures Manual are required. The
SKIM cannot be repaired, and if faulty or damaged,
the unit must be replaced.
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER
The Sentry Key Immobilizer System (SKIS) uses a
transponder that is integral to each of three ignitionkey that are supplied with the vehicle when it is
shipped from the factory. The transponder chip is
insulated within a nylon mount inserted in the head
of the key, and invisible beneath a molded rubber cap
(Fig. 2).
Each Sentry Key transponder has a unique tran-
sponder identification code programmed into it by the
manufacturer. The Sentry Key Immobilizer Module
(SKIM) has a unique ªSecret Keyº code programmed
into it by the manufacturer. When a Sentry Key
transponder is programmed into the memory of the
SKIM, the SKIM learns the transponder identifica-
tion code from the transponder, and the transponder
learns the ªSecret Keyº code from the SKIM. Each of
these codes is stored within the transponder and in
the nonvolatile memory of the SKIM. Therefore,
blank keys for the SKIS must be programmed by and
into the SKIM, in addition to being cut to match the
mechanical coding of the ignition lock cylinder. See
Sentry Key Immobilizer System Transponder Pro-
gramming in this group for more information.
The Sentry Key transponder is within the range of
the SKIM transceiver antenna ring when it is
inserted in the ignition lock cylinder. When the igni-
tion switch is turned to the START or RUN positions,
the SKIM transceiver issues a Radio Frequency (RF)
signal that excites the transponder chip. The tran-
sponder chip responds by issuing an RF signal con-
taining its transponder identification code and the
ªSecret Keyº code. The SKIM transceiver compares
the transponder codes with the codes stored in its
Fig. 2 Sentry Key Immobilizer Transponder
1 ± MOLDED CAP
2 ± TRANSPONDER
3 ± MOLDED CAP REMOVED
4 ± SENTRY KEY
PLVEHICLE THEFT/SECURITY SYSTEM 8Q - 3
DESCRIPTION AND OPERATION (Continued)

memory to determine whether a valid key is in the
ignition lock cylinder.
The Sentry Key transponder cannot be repaired
and, if faulty or damaged, it must be replaced.
SENTRY KEY IMMOBILIZER SYSTEM
INDICATOR LAMP
The Sentry Key Immobilizer System (SKIS) uses
the Vehicle Theft Security System (VTSS) indicator
LED to give an indication when the SKIS is faulty or
when the vehicle has been immobilized due to the
use of an invalid ignition key. The LED is controlled
by the instrument cluster circuitry based upon mes-
sages received from the Sentry Key Immobilizer
Module (SKIM) through the Body Control Module
(BCM) on the Programmable Communication Inter-
face (PCI) bus.
The SKIM sends messages to the instrument clus-
ter, via the BCM, to turn the LED on for about three
seconds when the ignition switch is turned to the ON
position as a bulb test. After completion of the bulb
test, the SKIM sends PCI bus messages to keep the
LED off for a duration of about one second. Then the
SKIM sends messages to the instrument cluster cir-
cuitry to turn the LED on or off based upon the
results of the SKIS self-tests. If the VTSS indicator
LED comes on and stays on after the bulb test, it
indicates that the SKIM has detected a system mal-
function and/or that the SKIS has become inopera-
tive. If the SKIM detects an invalid key when the
ignition switch is turned to the ON position, it sends
messages to the instrument cluster to flash the VTSS
indicator LED.
The SKIM can also send messages to the instru-
ment cluster to flash the LED and to generate a sin-
gle audible chime tone. These functions serve as an
indication to the customer that the SKIS has been
placed in its ªCustomer Learnº programming mode.
See Sentry Key Immobilizer System Transponder
Programming in this group for more information on
the ªCustomer Learnº programming mode.
The VTSS indicator LED uses a replaceable Light
Emitting Diode (LED) on the instrument cluster elec-
tronic circuit board. Refer to Group 8E - Instrument
Panel Systems for Cluster Lamp Removal and Instal-
lation. If the VTSS indicator LED comes on and
stays on after the bulb test function, diagnosis of the
SKIS should be performed with a DRB IIItscan tool
and the proper Body Diagnostic Procedures Manual.
TRIGGERING THE VTSS
After the VTSS is armed, any of the following will
trigger the system:
²Opening any door.
²Opening the hood.
²Removing the trunk lock cylinder.²Turning the ignition to the RUN/START position
with an invalid Sentry Key.
NOTE: The ignition switch can be turned to the
accessory position without triggering the alarm sys-
tem.
DIAGNOSIS AND TESTING
SENTRY KEY IMMOBILIZER SYSTEM
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
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 Immobilizer System (SKIS) involves the
use of a DRB lllTscan tool and the proper Body
Diagnostic Procedures Manual.
The Sentry Key Immobilizer System (SKIS) and
the Programmable Communication Interface (PCI)
bus network should be diagnosed using a DRB lllt
scan tool. The DRB IIItwill allow confirmation that
the PCI bus is functional, that the Sentry Key Immo-
bilizer Module (SKIM) is placing the proper messages
on the PCI bus, and that the Powertrain Control
Module (PCM) and the instrument cluster are receiv-
ing the PCI bus messages. Refer to the proper Body
Diagnostic Procedures Manual. Refer to Group
8W-Wiring Diagrams for complete circuit descriptions
and diagrams.
(1) Check the fuses in the fuse block. If OK, go to
Step 2. If not OK, repair the shorted circuit or com-
ponent as required and replace the faulty fuse.
(2) Disconnect and isolate the battery negative
cable (Fig. 3). Unplug the wire harness connector at
the SKIM. Check for continuity between the ground
circuit cavity of the SKIM 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
SKIM wire harness connector. If OK, go to Step 4. If
not OK, repair the open circuit to the fuse in the fuse
block as required.
8Q - 4 VEHICLE THEFT/SECURITY SYSTEMPL
DESCRIPTION AND OPERATION (Continued)