How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Hammer Time Your Own Question
Hammer Time
Hammer Time, L1 Master Technician
Category: Car
Satisfied Customers: 4942
Experience:  ASE Mastertech with Adv level Engine performance cert.
201885
Type Your Car Question Here...
Hammer Time is online now
A new question is answered every 9 seconds

98 Jeep Grand Cherokee: the vehicle theft security system module

Customer Question

Where is the vehicle theft security system module on a 98 Jeep Grand Cherokee, can I unplug it? Thank-you!! My 98 JGC factory installed alarm goes off at random. There is a brand new battery, but that did not help. I read about unplugging the VTSS module, but don't know where it is or how to do it properly. Will this solve my problem?
Submitted: 11 years ago.
Category: Car
Expert:  Stephen replied 11 years ago.


There is alot going on with the VTSS so it is possible that the
"randomness" of the alarm going off could be from activity on or around
the car.



I would think that the dealer could diable the alarm system for you.



I seem to remember on the CJ model that there was pink and white wire
that came off the BCM that could be re-routed to disable the
system. Not sure about that.



HTH.



Here is some information about the VTSS system from about.com





INTRODUCTION:

The Vehicle Theft Security System (VTSS) is an available
factory-installed option on versions of this model built for sale in
North America. This system is designed to provide perimeter protection
against unauthorized use or tampering by monitoring the vehicle doors,
liftgate, and ignition system. If unauthorized use or tampering is
detected, the system responds by sounding the horn, flashing the
exterior lamps, and providing an engine no-run feature. The VTSS can be
disarmed by unlocking the vehicle with the key in either front door
lock cylinder or using the Remote Keyless Entry (RKE) transmitters.




The
vehicle immobilizer system is factory-installed standard equipment on
models built for sale outside North America. Models equipped with the
vehicle immobilizer system cannot be equipped with the VTSS. The
vehicle immobilizer system is designed to provide passive protection
against unauthorized vehicle use by preventing the engine from
operating while the system is armed. The vehicle immobilizer system can
only be disarmed using the Remote Key-less Entry (RKE) transmitters.




Following
are some general descriptions of the features of the VTSS and the
vehicle immobilizer system. Refer to Power Lock Systems for more
information on the RKE system receiver and transmitters. Refer to
Vehicle Theft Security System for complete circuit descriptions and
diagrams.




NOTE:
This information covers both Left-Hand Drive (LHD) and Right-Hand Drive
(RHD) versions of this model. Whenever required and feasible, the RHD
versions of affected vehicle components have been constructed as
mirror-image of the LHD versions. While most of the illustrations used
represent only the LHD version, the diagnostic and service procedures
outlined can generally be applied to either version. Exceptions to this
rule have been clearly identified as LHD or RHD, if a special
illustration or procedure is required.




ENABLING




Vehicle Theft Security System:

The VTSS engine no-run feature is disabled when it is shipped from the
factory. This is done by programming within the Powertrain Control
Module (PCM) . The logic in the PCM prevents the VTSS engine no-run
feature from arming until the engine start counter within the PCM sees
twenty engine starts. The VTSS no-run feature must be enabled when the
vehicle is received from the assembly plant.




The
preferred method for enabling the VTSS engine no-run feature is to
electronically advance the PCM engine start counter using a DRB scan
tool. Refer to the Vehicle Theft Security System menu item on the DRB
scan tool for the procedures. Once this condition has been met, the PCM
will allow the engine no-run feature to arm.




Once the
VTSS engine no-run feature has been enabled, it cannot be disabled
unless the PCM is replaced with a new unit. The same VTSS engine no-run
feature enable logic will apply anytime the PCM is replaced with a new
unit.




Vehicle Immobilizer System:

The vehicle immobilizer system is disabled when it is shipped from the
factory. This is done by programming within the Powertrain Control
Module (PCM) and the Body Control Module (BCM) . The logic in the BCM
allows the vehicle immobilizer system functions to remain dormant in
vehicles sold in countries where it is not required. The logic in the
PCM prevents the immobilizer system from arming until the engine start
counter within the PCM sees twenty engine starts. The vehicle
immobilizer system must be enabled when the vehicle is received from
the assembly plant, if this feature is required or desired.




Once the
vehicle immobilizer system has been enabled, it cannot be disabled
unless the PCM and the BCM are replaced with new units. The same
vehicle immobilizer system enable logic will apply anytime the PCM
and/or the BCM are replaced with new units.




ARMING




Vehicle Theft Security System:

Passive arming of the VTSS occurs when the vehicle is exited with the
key removed from the ignition switch, the headlamps are turned off, and
the doors are locked using the power lock switch. The power lock switch
will not function if the key is in the ignition switch or the headlamps
are on with the driver side front door open. The VTSS will not arm if
either front door or the liftgate are locked using the key in the lock
cylinder.




Active
arming of the VTSS occurs when the Remote Keyless Entry (RKE)
transmitter is used to lock the vehicle, even if the doors and/or the
liftgate are open when the RKE transmitter Lock button is depressed.
However, the VTSS arming will not be complete until all the doors and
the liftgate are closed.




Following
successful passive or active VTSS arming, the VTSS set lamp on the top
of the instrument panel will flash rapidly for about fifteen seconds
after the illuminated entry system times out. This indicates that VTSS
arming is in progress. Once the fifteen second arming function is
complete, the set lamp will flash at a slower rate to indicate that the
VTSS is armed.




Vehicle Immobilizer System:

Active arming of the vehicle immobilizer system occurs when the vehicle
is locked using the power lock switch or when the Lock button of the
Remote Keyless Entry (RKE) transmitter is used to lock the vehicle.
Arming will occur, even if the doors and/or the liftgate are open when
the vehicle is locked, as long as the ignition switch is in the Off
position. The vehicle immobilizer system cannot be actively armed while
the ignition switch is in the On or Start positions.




Passive
arming of the system occurs when the ignition switch is in the Off
position for more than five minutes (one minute for vehicles sold in
the United Kingdom). See Power-Up Mode for a description of other
conditions that can result in passive arming of the vehicle immobilizer
system.




Following
receipt of a passive or active request for arming of the vehicle
immobilizer system, a set lamp located on top of the instrument panel
will begin to flash rapidly for fifteen seconds . Following successful
vehicle immobilizer system arming (about fifteen seconds ), the set
lamp will continue to flash, but at a much slower rate. The slow
flashing of the set lamp will continue for as long as the vehicle
immobilizer system is armed.




DISARMING




Vehicle
Theft Security System Passive disarming of the VTSS occurs when the
vehicle is unlocked using the key to unlock either front door or the
liftgate. Active disarming of the VTSS occurs when the vehicle is
unlocked by depressing the Unlock button of the Remote Keyless Entry
(RKE) transmitter.




Once the
alarm has been activated (horn sounding, lights flashing, and the
engine no-run feature), either disarming method will also deactivate
the alarm.




Depressing
the Panic button on the RKE transmitter will also disarm the VTSS, but
the horn will sound and the lights will flash for about three minutes
as part of the Panic feature. Refer to Power Lock Systems for more
information on the Panic feature.




Vehicle Immobilizer System:

Active disarming of the vehicle immobilizer system occurs when the
Unlock button of either of the two Remote Keyless Entry (RKE)
transmitters is depressed, regardless of ignition switch position. This
is the only way that the vehicle immobilizer system can be disarmed.
Following successful disarming of the vehicle immobilizer system, the
set lamp on top of the instrument panel will stop flashing.




POWER-UP MODE




Vehicle Theft Security System:

When the armed VTSS senses that the battery has been disconnected and
reconnected, it enters its power-up mode. In the power-up mode the
alarm system remains armed following a battery failure or disconnect.
If the VTSS was armed prior to a battery disconnect or failure, the
system will have to be actively or passively disarmed after the battery
is reconnected.




The
power-up mode will also apply if the battery goes dead while the system
is armed, and battery jump-starting is attempted. The engine no-run
feature will prevent the engine from starting until the alarm system
has been actively or passively disarmed.




Vehicle Immobilizer System:

When the vehicle immobilizer system senses that the vehicle battery has
been disconnected and reconnected, it enters its power-up mode. If the
immobilizer system was armed prior to the battery disconnect, the
system remains armed when the battery is reconnected.




If the
immobilizer system was disarmed prior to the battery disconnect, the
system will remain disarmed if the battery is reconnected within five
minutes (one minute for vehicles sold in the United Kingdom). The
system will passively arm itself when the battery is reconnected more
than five minutes (one minute for vehicles sold in the United Kingdom)
after a battery disconnect or failure. After any passive arming, the
system will have to be actively disarmed by depressing the Unlock
button on one of the Remote Keyless Entry (RKE) transmitters.




The
power-up mode logic also applies if the battery goes dead, and battery
jump-starting is attempted. The engine no-run feature will prevent the
engine from operating until the vehicle immobilizer system has been
actively disarmed.




TAMPER ALERT:

The VTSS tamper alert will sound the horn three times upon disarming,
if the alarm was activated and has since timed-out (about eighteen
minutes ). This feature alerts the driver that the VTSS was activated
while the vehicle was unattended.




CIRCUIT OPERATION:

Each door, the liftgate, hood, and the liftglass in the liftgate have
an ajar switch that connects to the Body Control Module (BCM) . The
ajar switches are normally open when the doors, liftgate, liftglass and
hood are closed. When one of them open, its ajar switch closes and
connects the BCM to ground. In response, if the Vehicle Theft Security
System is armed, the BCM starts the alarm. Refer to the Introduction in
this section for alarm information.




The BCM receives the ajar switch signals on the following circuits.





  • Circuit G75 provides left front door ajar switch signal
  • Circuit G74 provides right front door ajar switch signal
  • Circuit G77 provides left rear door ajar switch signal
  • Circuit G76 provides right rear door ajar switch signal
  • Circuit G78 provides liftgate ajar and liftglass ajar signals.



























Customer: replied 11 years ago.
Reply to Stephen's Post: Hi Stephen,

I really appreciate the time you spent or your answer, but telling me the dealer could disable it is not what I was looking for. As for the pink wire, that was really too vague for me to do anything with. I thought I would get a reply from someone who has done this before and could advise me exactly how to do the same, although I may have been expecting too much. Again thank you for your time.

Nanci
Expert:  Hammer Time replied 11 years ago.
That's a highly technical security system that is integrated throughout the computer and electrical system. If it was as simple as you would like it to be, it would be much of a security system now, would it?

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
< Previous | Next >
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim Castleberry, FL
  • Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV. Dutch USA
 
 
 

Meet The Experts:

 
 
 
  • Chris (aka-Moose)

    Chris (aka-Moose)

    Technician

    Satisfied Customers:

    1006
    16 years of experience
< Last | Next >
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Technician

    Satisfied Customers:

    1006
    16 years of experience
  • http://ww2.justanswer.com/uploads/TE/TedG/2012-6-15_14759_avaLarge.64x64.jpg Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Satisfied Customers:

    1694
    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    1447
    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • http://ww2.justanswer.com/uploads/BL/Bluegorilla/2012-6-21_16298_cam.64x64.JPG GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Auto Service Tech

    Satisfied Customers:

    669
    GM Grand Master Technician 2007. 14 years experience.
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    Former ASE Master Tech

    Satisfied Customers:

    2406
    ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    2123
    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    992
    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes