2003 JEEP GRAND CHEROKEE Air con

(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)

cylinder lock switches are driven by the key lock cyl-
inders and contain two internal resistors. One resis-
tor value is used for the Lock position, and one for
the Unlock position.
The door cylinder lock switches cannot be adjusted
or repaired and, if faulty or damaged, they must be
replaced.
OPERATION
The door cylinder lock switches are actuated by the
key lock cylinder when the key is inserted in the lock
cylinder and turned to the lock or unlock positions.
The door cylinder lock switch close a circuit between
the door lock switch ground circuit and the left or
right cylinder lock switch mux circuits through one of
two internal resistors for the Driver Door Module
(DDM) when either front door key lock cylinder is in
the Lock, or Unlock positions. The DDM reads the
switch status through an internal pull-up, then uses
this information as an input for the Vehicle Theft
Security System (VTSS) operation.
The door cylinder lock switches and circuits can be
diagnosed using conventional diagnostic tools and
methods.
DIAGNOSIS AND TESTING - DOOR CYLINDER
LOCK SWITCH
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.(1) Disconnect the door cylinder lock switch pigtail
wire connector from the door wire harness connector.
(2) Using a ohmmeter, check the switch resistance
checks between the two terminals in the door cylin-
der lock switch pigtail wire connector. Actuate the
switch by rotating the key in the door lock cylinder
to test for the proper resistance values in each of the
two switch positions, as shown in the Door Cylinder
Lock Switch Test table.
DOOR CYLINDER LOCK SWITCH TEST
Switch Position Resistance
( 10%)
Left Side Right Side
Lock (Clockwise) Unlock
(Counterclockwise)473 Ohms
Unlock
(Counterclockwise)Lock (Clockwise) 1.994
Kilohms
(3) If a door cylinder lock switch fails either of the
resistance tests, replace the faulty switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the outside door handle unit from the
outer door panel. (Refer to 23 - BODY/DOOR -
FRONT/EXTERIOR HANDLE - REMOVAL).
(3) Remove the retainer clip from the pin on the
back of the door lock cylinder (Fig. 2).
(4) Remove the lock lever from the pin on the back
of the door lock cylinder.
Fig. 1 DOOR CYLINDER LOCK SWITCH
1 - SWITCH
2 - OUTSIDE DOOR HANDLE
3 - DOOR LOCK CYLINDER
Fig. 2 LOCK CYLINDER LEVER RETAINER RE
1 - LEVER
2 - RETAINER
3 - LOCK CYLINDER
4 - SWITCH
5 - PLIERS
6 - OUTSIDE DOOR HANDLE
8Q - 8 VEHICLE THEFT SECURITYWJ
DOOR CYLINDER LOCK SWITCH (Continued)

(5) Remove the door cylinder lock switch from the
back of the lock cylinder.
INSTALLATION
(1) Position the door cylinder lock switch onto the
back of the lock cylinder with its pigtail wire harness
oriented toward the bottom (Fig. 2).
(2) Position the lock lever onto the pin on the back
of the door lock cylinder with the lever oriented
toward the rear.
(3) Install the retainer clip onto the pin on the
back of the door lock cylinder. Be certain that the
center tab of the retainer is engaged in the retention
hole on the lock lever.
(4) Reinstall the outside door handle unit onto the
outer door panel. (Refer to 23 - BODY/DOOR -
FRONT/EXTERIOR HANDLE - INSTALLATION).
(5) Reconnect the battery negative cable.
HOOD AJAR SWITCH
DESCRIPTION
The hood ajar switch is a self-adjusting, normally
closed, single pole, double throw momentary switch
that is used only on vehicles built for sale in certain
international markets where it is required equipment
(Fig. 3). The mounting bracket is fastened to the left
inner fender. A molded plastic striker with three inte-
gral retainers is secured to the underside of the hood
panel inner reinforcement to actuate the switch
plunger as the hood panel is closed.The switchreceives a path to ground through the left inner
fender shield in the engine compartment.
The hood ajar switch adjusts itself as the striker
pushes the switch body down through the switch
when the hood panel is closed after the initial instal-
lation. This self-adjustment feature is only functional
the first time the hood is closed following installa-
tion. If the switch requires adjustment following the
initial installation, the switch must be replaced.
OPERATION
The normally closed hood ajar switch is normally
held open when the hood panel is closed and latched.
When the hood is opened, the switch plunger extends
from the switch body and the switch contacts are
closed. The hood ajar switch is connected in series
between ground and the hood ajar switch sense input
of the Body Control Module (BCM). The BCM uses
an internal resistor pull up to monitor the state of
the hood ajar switch contacts. The hood ajar switch
can be diagnosed using conventional diagnostic tools
and methods.
DIAGNOSIS AND TESTING - HOOD AJAR
SWITCH
The diagnosis found here addresses an inoperative
hood ajar switch. If the problem being diagnosed is
related to hood ajar switch accuracy, be certain to
confirm that the problem is not an improperly
adjusted hood ajar switch. If no hood ajar switch
adjustment problem is found, the following procedure
will help to locate a short or open in the hood ajar
switch circuit. Refer to the appropriate wiring infor-
mation.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable. Disconnect the hood ajar switch. Check for
continuity between the harness ground circuit a good
ground. There should be continuity. If OK, go to Step
2. If not OK, repair the open ground circuit to
ground.
Fig. 3 Hood Ajar Switch
1 - SWITCH
2 - STUD (2)
3 - BRACKET
4 - FENDER
5 - CONNECTOR
6 - NUT (2)
WJVEHICLE THEFT SECURITY 8Q - 9
DOOR CYLINDER LOCK SWITCH (Continued)

(2) Check for continuity between the two terminals
of the hood ajar switch. There should be continuity
with the switch plunger extended, and no continuity
with the switch plunger depressed. If OK, go to Step
3. If not OK, replace the faulty hood ajar switch.
(3) Disconnect the instrument panel wire harness
connector from the Body Control Module (BCM).
Check for continuity between the hood ajar switch
sense circuit of the hood ajar switch and a good
ground. There should be no continuity. If OK, go to
Step 4. If not OK, repair the shorted hood ajar switch
sense circuit between the hood ajar switch and the
BCM.
(4) Check for continuity between the hood ajar
switch sense circuit and the instrument panel wire
harness connector for the BCM. There should be con-
tinuity. If OK, proceed to diagnosis of the Vehicle
Theft Security System (VTSS). (Refer to 8 - ELEC-
TRICAL/VEHICLE THEFT SECURITY - DIAGNO-
SIS AND TESTING). If not OK, repair the open hood
ajar switch sense circuit between the hood ajar
switch and the BCM.
REMOVAL
REMOVAL - HOOD AJAR SWITCH
(1) Open the hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Squeeze the two switch latch tabs together and
pull the switch upward (Fig. 3)
(4) Disconnect the wiring harness connector.
(5) Remove the hood ajar switch from the mount-
ing bracket.
REMOVAL - HOOD AJAR SWITCH BRACKET
(1) Remove the hood ajar switch from the mount-
ing bracket. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY/HOOD AJAR SWITCH -
REMOVAL).
(2) Remove the two nuts that secure the hood ajar
switch bracket to the left inner fender (Fig. 3)
(3) Remove the hood ajar switch bracket from the
studs on the left inner fender.
REMOVAL - HOOD AJAR SWITCH STRIKER
(1) Open the hood.
(2) Using a trim stick or another suitable wide
flat-blade tool, gently raise the hood ajar switch
striker away from the inner hood panel reinforce-
ment, and remove. (Fig. 4).
INSTALLATION
INSTALLATION - HOOD AJAR SWITCH
(1) Position the hood ajar switch into the hole in
the mounting bracket (Fig. 3)
(2) Reconnect the wiring harness connector.
(3) Press the switch downward into the mounting
bracket until the latch tabs lock it into place.
(4) Reconnect the battery negative cable.
(5) Close and latch the hood.
INSTALLATION - HOOD AJAR SWITCH
BRACKET
(1) Position the hood ajar switch bracket onto the
studs on the left inner fender (Fig. 3)
(2) Install and tighten the two nuts. Tighten the
nuts to 11.8 N´m (105 in. lbs.).
(3) Reinstall the hood ajar switch into the mount-
ing bracket. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY/HOOD AJAR SWITCH -
INSTALLATION).
Fig. 4 Hood Ajar Switch Striker
1 - REINFORCEMENT
2 - STRIKER
3 - HOOD
8Q - 10 VEHICLE THEFT SECURITYWJ
HOOD AJAR SWITCH (Continued)

INSTALLATION - HOOD AJAR SWITCH
STRIKER
(1) Align the three integral retainers of the hood
ajar switch striker with their mounting holes in the
inner hood panel reinforcement (Fig. 4).
(2) Using hand pressure, firmly press the hood
ajar switch striker against the inner hood panel rein-
forcement until all of the striker retainers are fully
engaged in their mounting holes.
(3) Close and latch the hood.
INTRUSION TRANSCEIVER
MODULE
DESCRIPTION
An Intrusion Transceiver Module (ITM) is part of
the premium version of the Vehicle Theft Alarm
(VTA) in the Vehicle Theft Security System (VTSS)
(Fig. 5). The premium version of the VTA is only
available in vehicles built for certain markets, where
the additional features offered by this system are
required. The ITM is located in the passenger com-
partment. This unit is designed to provide interior
motion detection, and serve as an interface between
the Body Control Module (BCM) and the alarm siren
module.
The ITM is concealed beneath a dedicated molded
plastic trim cover that approximates the size and
shape of a typical dome lamp housing. However,
rather than a lens, the ITM features three sets of
louvered openings. One set of louvered openings is
located at each outboard end of the center rib, while
the third set is centered. Each of the louvered open-
ings is covered on the inside by a sight shield thatextends the length of the center rib. The module is
secured to a mounting bracket above the headliner
(Fig. 6).
Concealed within the housing is the circuitry of the
ITM which includes a microprocessor, and an ultra-
sonic receive transducer. Both the transmit trans-
ducer on the right side of the module and the receive
transducer on the ITM circuit board are aimed
through two small round holes in the sight shield of
the trim cover. The ITM is connected to the vehicle
electrical system by a take out and connector of the
overhead wire harness that is integral to the head-
liner.
The ITM unit cannot be adjusted or repaired and,
if faulty or damaged, it must be replaced. The ITM is
serviced as a unit with the trim cover.
OPERATION
The microprocessor in the Intrusion Transceiver
Module (ITM) contains the motion sensor logic cir-
cuits and controls all of the features of the premium
version of the Vehicle Theft Alarm (VTA). The ITM
uses On-Board Diagnostics (OBD) and can communi-
cate with other modules in the vehicle as well as
with the DRBIIItscan tool using the Programmable
Communications Interface (PCI) data bus network.
This method of communication is used by the ITM to
communicate with the Body Control Module (BCM)
and for diagnosis and testing. The ITM also commu-
nicates with the alarm siren over a dedicated serial
bus circuit.
Fig. 5 INTRUSION TRANSCEIVER MODULE
1 - ITM
2 - HEADLINER
Fig. 6 INTRUSION TRANSCEIVER MODULE
1 - TRIM COVER
2 - CONNECTOR RECEPTACLE
3 - HOUSING
4 - SCREW (4)
5 - SERVICE HOLE (2)
6 - LATCH FEATURE (4)
WJVEHICLE THEFT SECURITY 8Q - 11
HOOD AJAR SWITCH (Continued)

the two rear latch receptacles of the mounting
bracket above the headliner.
(5) Push upward firmly and evenly on the rear
edge of the ITM trim cover until the two rear latch
features of the module are engaged and latched in
the mounting bracket above the headliner.
(6) Reconnect the battery negative cable.
NOTE: If the Intrusion Transceiver Module (ITM) has
been replaced with a new unit, the new ITM MUST
be initialized before the Vehicle Theft Security Sys-
tem can operate as designed. The use of a DRBIIIT
scan tool is required to initialize the ITM. Refer to
the appropriate diagnostic information.
SIREN
DESCRIPTION
An alarm siren module is part of the premium ver-
sion of the Vehicle Theft Alarm (VTA) in the Vehicle
Theft Security System (VTSS) (Fig. 9). The premium
version of the VTA is only available in vehicles built
for certain markets, where the additional features
offered by this system are required. The alarm siren
module is located in the right front frame rail. This
unit is designed to provide the audible alert require-
ments for the premium VTA.
The alarm siren module consists of microprocessor,
the siren, and a nickel metal hydride backup battery.
All of the alarm module components are protected
and sealed within the housing.The alarm siren module cannot be repaired or
adjusted and, if faulty or damaged, it must be
replaced.
OPERATION
The microprocessor within the alarm siren module
provides the siren unit features and functions based
upon internal programming and arm and disarm
messages received from the Intrusion Transceiver
Module (ITM) over a dedicated serial bus communi-
cation circuit. The alarm siren module will self-detect
problems with its internal and external power supply
and communication circuits, then send messages
indicating the problem to the ITM upon receiving a
request from the ITM. The ITM will store a Diagnos-
tic Trouble Code (DTC) for a detected alarm siren
module fault that can be retrieved with the DRBIIIt
scan tool over the Programmable Communications
Interface (PCI) data bus.
When the premium version of the Vehicle Theft
Alarm (VTA) is armed, the alarm siren module con-
tinuously monitors inputs from the ITM for messages
to sound its siren and enters its auto-detect mode.
While in the auto-detect mode, if the alarm siren
module detects that its power supply or communica-
tion circuits are being tampered with or have been
sabotaged, it will sound an alarm and continue to
operate through its on-board backup battery. If the
arm siren module is in its disarmed mode when its
power supply or communication circuits are inter-
rupted, the siren will not sound. The alarm module
will also notify the ITM when the backup battery
requires charging, and the ITM will send a message
that will allow the backup battery to be charged
through the battery voltage and ground circuits to
the alarm module only when the ignition switch is in
the On position and the engine is running. This will
prevent the charging of the alarm backup battery
from depleting the charge in the main vehicle battery
while the vehicle is not being operated.
The alarm siren module receives battery voltage
through a fuse in the Power Distribution Center
(PDC), and is grounded to the chassis. These connec-
tions allow the alarm siren module to remain opera-
tional, regardless of the ignition switch position. The
hard wired inputs and outputs for the alarm siren
module may be diagnosed and tested using conven-
tional diagnostic tools and procedures. However, con-
ventional diagnostic methods will not prove
conclusive in the diagnosis of the internal circuitry or
the backup battery of the alarm siren module, the
ITM, the serial bus communication line, or the mes-
sage inputs to and outputs from the alarm siren
module. The most reliable, efficient, and accurate
means to diagnose the alarm siren module, the ITM,
the serial bus communication line, and the electronic
Fig. 8 INTRUSION TRANSCEIVER MODULE
RETAINER RING
1 - STAMPED NUT (2)
2 - MOUNTING BRACKET
3 - HEADLINER
4 - LATCH RECEPTACLES (4)
WJVEHICLE THEFT SECURITY 8Q - 13
INTRUSION TRANSCEIVER MODULE (Continued)

cluster circuitry that controls the lamp, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). If the instrument cluster turns
on the SKIS indicator lamp after the bulb test, either
solid or flashing, it indicates that a SKIS malfunction
has occurred or that the SKIS is inoperative. For
proper diagnosis of the SKIS, the PCI data bus, or
the message inputs to the instrument cluster that
control the SKIS indicator lamp, a DRBIIItscan tool
and the appropriate diagnostic information are
required.
TRANSPONDER KEY
DESCRIPTION
Each ignition key used in the Sentry Key Immobi-
lizer System (SKIS) has an integral transponder chip
(Fig. 10). Ignition keys with this feature can be
readily identified by a gray rubber cap molded onto
the head of the key, while conventional ignition keys
have a black molded rubber cap. The transponder
chip is concealed beneath the molded rubber cap,
where it is molded into the head of the metal key.
Each new Sentry Key has a unique transponder iden-
tification code permanently programmed into it by
the manufacturer. The Sentry Key transponder if
faulty or damaged, must be replaced.
OPERATION
When the ignition switch is turned to the On posi-
tion, the Sentry Key Immobilizer Module (SKIM)communicates through its antenna with the Sentry
Key transponder using a Radio Frequency (RF) sig-
nal. The SKIM then waits for a RF response from the
transponder through the same antenna. The Sentry
Key transponder chip is within the range of the
SKIM transceiver antenna ring when it is inserted
into the ignition lock cylinder. The SKIM determines
whether a valid key is present in the ignition lock
cylinder based upon the response from the transpon-
der. If a valid key is detected, that fact is communi-
cated by the SKIM to the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus, and the PCM allows the
engine to continue running. If the PCM receives an
invalid key message, or receives no message from the
SKIM over the PCI data bus, the engine will be dis-
abled after about two seconds of operation. The Elec-
troMechanical Instrument Cluster (EMIC) will also
respond to the invalid key message on the PCI data
bus by flashing the SKIS indicator on and off.
Each Sentry Key has a unique transponder identi-
fication code permanently programmed into it by the
manufacturer. Likewise, the SKIM has a unique
Secret Key code programmed into it by the manufac-
turer. When a Sentry Key is programmed into the
memory of the SKIM, the SKIM stores the transpon-
der identification code from the Sentry Key, and the
Sentry Key learns the Secret Key code from the
SKIM. Once the Sentry Key learns the Secret Key
code of the SKIM, it is permanently stored in the
memory of the transponder. Therefore, once a Sentry
Key has been programmed to a particular vehicle, it
cannot be used on any other vehicle. (Refer to 8 -
ELECTRICAL/VEHICLE THEFT SECURITY -
STANDARD PROCEDURE - TRANSPONDER PRO-
GRAMMING).
VTSS INDICATOR
DESCRIPTION
The Vehicle Theft Security System (VTSS) indica-
tor consists of a red Light-Emitting Diode that is
mounted and integral to the automatic headlamp
light sensor photo diode unit, which is located on the
top of the instrument panel. The remainder of the
housing including the mount and the electrical con-
nection are concealed beneath the instrument panel
top cover.
The VTSS indicator cannot be adjusted or repaired
the entire automatic headlamp light sensor/VTSS
indicator must be replaced. (Refer to 8 - ELECTRI-
CAL/LAMPS/LIGHTING - EXTERIOR/AUTO HEAD-
LAMP SENSOR - REMOVAL).
Fig. 10 Sentry Key Immobilizer Transponder
1 - MOLDED CAP
2 - TRANSPONDER CHIP
3 - MOLDED CAP REMOVED
4 - TRANSPONDER KEY
WJVEHICLE THEFT SECURITY 8Q - 15
SKIS INDICATOR LAMP (Continued)

OPERATION
The Vehicle Theft Security System (VTSS) indica-
tor gives a visible indication of the VTSS arming sta-
tus. One side of Light-Emittiong Diode (LED) in the
VTSS indicator is connected to unswitched battery
current through a fused B(+) circuit and a fuse in the
Junction Block (JB). The other side of the LED is
hard wired to the Body Control Module (BCM), which
controls the operation of the VTSS indicator by pull-
ing this side of the LED circuit to ground. When the
VTSS arming is in progress, the BCM will flash the
LED rapidly on and off for about fifteen seconds.
When the VTSS has been successfully armed, the
BCM will flash the LED on and off continually at a
much slower rate until the VTSS has been disarmed.
The VTSS indicator can be diagnosed using conven-
tional diagnostic tools and methods.
DIAGNOSIS AND TESTING - VTSS INDICATOR
The diagnosis found here addresses an inoperative
Vehicle Theft Security System (VTSS) indicator con-
dition. If the problem being diagnosed is related to
indicator accuracy, be certain to confirm that the
problem is with the indicator and not with an inop-
erative VTSS. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY - DIAGNOSIS AND TESTING -
VEHICLE THEFT SECURITY SYSTEM). If no VTSS
problem is found, the following procedure will help to
locate a short or open in the VTSS indicator control
circuit. Refer to the appropriate wiring information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Check the fused B(+) fuse in the Junction
Block (JB). If OK, go to Step 2. If not OK, repair the
shorted circuit or component and replace the faulty
fuse.
(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 fused B(+) circuit between the JB and the
Power Distribution Center (PDC).
(3) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the automatic headlamp light sensor/
VTSS indicator from the automatic headlamp light
sensor/VTSS indicator pigtail wire connector. Recon-
nect the battery negative cable. Check for battery
voltage at the fused B(+) circuit cavity of the instru-
ment panel wire harness connector for the automatic
headlamp light sensor/VTSS indicator. If OK, go to
Step 4. If not OK, repair the open fused B(+) circuit
between the VTSS indicator and the JB.
(4) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the JB from the JB connector recepta-
cle. Check for continuity between the VTSS indicator
driver circuit cavity of the instrument panel wire
harness connector for the automatic headlamp light
sensor/VTSS indicator and a good ground. There
should be no continuity. If OK, go to Step 5. If not
OK, repair the shorted VTSS indicator driver circuit
between the VTSS indicator and the JB.
(5) Check for continuity between the VTSS indica-
tor driver circuit of the instrument panel wire har-
ness connector for the automatic headlamp light
sensor/VTSS indicator and the instrument panel wire
harness connector for the JB. There should be conti-
nuity. If OK, replace the faulty VTSS indicator. If not
OK, repair the open VTSS indicator driver circuit
between the VTSS indicator and the JB.
8Q - 16 VEHICLE THEFT SECURITYWJ
VTSS INDICATOR (Continued)