Security system

Tiny
CC49
  • MEMBER
  • 2003 JEEP LIBERTY
  • 140,000 MILES
Hi, is there a security system in this model Jeep? Because we only got one key to it. Just bought it from someone. Help! Any information would be great.
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Sunday, March 10th, 2019 AT 2:20 PM

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Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi and thanks for using 2CarPros.

These vehicles did come with an anti theft immobilizer system. What I suggest is to return to a dealer and have them reproduce the key for the vehicle.

Here is a complete description of the system and how it works on the vehicle. It is somewhat complex, but I thought I would add this for you.

_________________________________

2003 Jeep Truck Liberty 4WD V6-3.7L VIN K
Components
Vehicle Accessories and Optional Equipment Antitheft and Alarm Systems Description and Operation Components
COMPONENTS
Sentry Key Immobilizer System (SKIS) Overview
The Sentry Key Immobilizer System (SKIS) is an immobilizer system designed to prevent unauthorized vehicle operation. The system consists of a Sentry Key Immobilizer Module (SKIM) sends a PCI Bus message to the engine controller indicating ignition key status. Upon receiving this message the PCM will terminate engine operation or allow the engine to continue to operate.

Sentry Key Immobilizer System (SKIS) Operation
When ignition power is supplied to the SKIM, the SKIM performs an internal self-test. After the self-test is completed, the SKIM energizes the antenna (this activates the transponder chip) and sends a challenge to the transponder chip. The transponder chip responds to the challenge by generating an encrypted response message using the following:

Secret Key - This is an electronically stored value (identification number) that is unique to each SKIS. The secret key is stored in the SKIM, PCM and all ignition key transponders.

Challenge - This is a random number that is generated by the SKIM at each ignition key cycle. The secret key and challenge are the two variables used in the algorithm that produces the crypto algorithm to receive, decode and respond to the message sent by the SKIM. After responding to the coded message, the transponder sends a transponder ID message to the SKIM. The SKIM compares the transponder ID to the available valid ignition key codes in the SKIM memory (8 key maximum). After validating the key, the SKIM sends a PCI Bus message called a "Seed Request" to the engine controller then waits for a PCM response. If the PCM does not respond, the SKIM will send the seed request again. After three failed attempts, the SKIM Will stop sending the seed request and store a trouble code. If the PCM sends a seed response, the SKIM sends a valid/invalid key message to the PCM. This is an encrypted message that is generated using the following:

VIN - Vehicle Identification Number

Seed - This is a random number that is generated by the PCM at each ignition key cycle.

The VIN and Seed are the two variables used in the rolling code algorithm that encrypts the "valid/invalid key" message. The PCM used the rolling code algorithm to receive, decode and respond to the valid/invalid key message sent by the SKIM. After sending the valid/invalid key message the SKIM waits 3.5 seconds for a PCM status message from the PCM. If the PCM does not respond with a valid key message to the SKIM, a fault is detected and a trouble code is stored. The SKIS incorporates a warning lamp located in the instrument cluster. The lamp receives power and ground from the instrument cluster. The lamp is actuated when the SKIM sends a PCI Bus message to the instrument cluster requesting the lamp on.

The SKIM will request warning lamp illumination for:
- bulb checks at ignition on
- to alert the vehicle operator to a SKIS malfunction
- customer key programming mode

For all faults except transponder faults and VIN mismatch, the lamp remains on steady. In the event of a transponder fault the light flashes at a rate of 1 Hz (once per second). If a fault is present the lamp will remain on or flashing for the complete ignition cycle. If a fault is stored in SKIM memory which prevents the system from operating properly, the PCM will allow the engine to start and run (for 2 seconds) up to six times. After the sixth attempt the PCM will not allow the engine to start.

VEHICLE THEFT SECURITY SYSTEM (VTSS)
The BCM controls the VTSS if equipped. To arm the VTSS the BCM will begin the VTSS Prearming process, which last for sixteen seconds after the following criteria is met. The key is removed from the ignition switch and the operator locks the vehicle using a key fob or power door lock switch with the doors closed or if the doors are open it will then begin when all doors are closed. During Pre-arm, the VTSS indicator located in the Instrument Cluster flashes two times per second. Prearm is exited if any door/tailgate is opened, flip-up glass is opened, a cylinder lock switch is turned to unlock, or the ignition is turned on.

After the Pre-arm timer expires, the BCM goes to the armed mode and flashes the VTSS indicator at a slower rate. The BCM monitors the door ajar, flip-up glass ajar, tailgate ajar and ignition status and trips to alarming if any of these change states.

Disarming the VTSS feature is done with the left key cylinder lock switch, a Remote Keyless Entry system "unlock" or the ignition turned to the "on" position with a valid SKIM key.

If the BCM is triggered to the Alarm state, it flashes the headlamps, hazard lamps and actuates the Horn on and off for 3 minutes, then will flash the headlamps and hazard lamps without the horn for an additional 15 minutes until it times out. After the timeout, the alarm will return to the armed state. If the alarm was triggered while the operator was away from the vehicle, the BCM will chirp the horn 3 times ("Tamper Alert") when the driver disarms the alarm.

Vehicle Theft Security System (VTSS) (Export Only)
The Vehicle Theft Security System (VTSS) is available in either a base or a premium version for this model. The base system is controlled by the Body Control Module (BCM) while the premium system is controlled by the BCM along with an Intrusion Transceiver Module (ITM) which monitors the interior of the vehicle for movement. The base VTSS uses the vehicle horn for the audible alert while the premium version is equipped with a battery backed siren. Both systems will flash the hazard lamps when tripped. The VTSS does not prevent engine operation, this is done with the Sentry Key Immobilizer System SKIS. For information regarding SKIS, refer to the appropriate Powertrain Diagnostic Procedures.

To arm the VTSS the BCM must complete a sixteen-second Pre-arming process, which will begin after the following criteria are met. The key is removed from the ignition switch and the operator locks the vehicle using a key fob or power door lock switch with the doors, tailgate and flip-up glass closed or if any of these are open, pre-arm will begin after they are closed. If the hood is left open during pre-arming it will be ignored as input until it is closed. During Pre-arming, the VTSS indicator located in the Instrument Cluster flashes two times per second. Pre-arm is exited if any doors, tailgate, flip-up glass or the hood is opened, or if the ignition switch is turned to the on position.

After the Pre-arming timer expires, the BCM goes to the armed mode and flashes the VTSS indicator at a slower rate. The BCM will then monitor the ignition switch status along with the hood/door/flip-up glass/tailgate ajar switches. For vehicles equipped with the Intrusion Transceiver Module the vehicle's interior will continuously be monitored for movement. This feature can be disabled during the pre-arm sequence with three additional lock commands from the RKE which will cause a single audible chirp confirming this request. While armed the Siren will continuously monitor it's battery feed and the siren signal control circuits and will trigger if either of these are disconnected. The Siren also sends a status message back to the ITM.

Disarming the VTSS is done with either a Remote Keyless Entry system "unlock" or the ignition turned to the "on" position with a valid SKIM key.

When the VTSS is triggered on a base system, the alarming state will be twenty-five seconds. Vehicles with the premium system will actuate the hazard lamps for twenty-five seconds and the siren twenty-eight seconds. After that period if the disturbance is still present only the siren will be activated again for twenty-eight seconds with five seconds intervals between warning cycles. This will continue up to ten times unless the disturbance goes away. If the alarm was triggered while the operator was away from the vehicle, there will be three audible chirp messages when the system is disarmed.

The BCM controls the Front Windshield Wipers via the On/Off and Hi/Low relays located in the Power Distribution Center (PDC), based on input from the Front Wiper Mode Switch. NOTE: The BCM does not control the rear wiper system, however, the BCM does monitor the Rear Wiper Mode Switch to control the flip-up glass release. This function is discussed under Power Door Locks.

If the Front Wiper Mode Switch is in any of the Intermittent Delay positions, the BCM will turn on the On/ Off relay until the wiper motor is off of the Park Switch. The internal wiring between the motor and the relays, allows the wipers to complete a single cycle and return to the parked position. The BCM monitors the Park Switch to make sure that the Wiper is able to return to the parked position within 8 seconds. If this does not occur, the BCM sets a Wiper Park Switch DTC and turns the wiper on/off relay to on until the wipers are switched off.

If the Front Wiper Mode Switch is in the Low position, the BCM will turn on the On/Off relay. The wiper motor will run at low speed.

If the Front Wiper Mode Switch is in the High position, the BCM will turn on the On/Off relay and the Hi/Low relay. The wiper motor will run at high speed.

If the Front Wiper Mode Switch is turned to the Wash position, the BCM will turn on the On/Off relay until it sees 3 cycles of the park switch. The wiper motor will run at low speed for 3 cycles and then resume whatever the current mode of the switch is.

THE BCM IS ALSO INVOLVED IN THE FOLLOWING FUNCTIONS:

Vehicle Speed Sensing
The speed sensor on the rear axle generates approximately 80,000 pulses per mile. This signal is sent to the ABS module (if equipped) and then to the BCM. The BCM has been programmed in the Assembly Plant with the proper tire size. If a BCM is replaced, it must be programmed with the proper tire size using the DRB III (R). Based on this tire size, the BCM converts the 80,000 pulses per mile into 8,000 pulses per mile, and outputs this signal to the PCM.

If the vehicle is equipped with ABS, the ABS module supplies the required 12V DC to the wheel speed sensor. If the vehicle is not equipped with ABS, the BCM supplies this voltage on the Vehicle Speed Sensor Supply pin. This output is on for non-ABS vehicles when the ignition switch is in the Run or Crank positions.

Detection / Analysis Of Miscellaneous Body Switches
The BCM detects the position of the A/C Switch from the control head and reports this over the PCI bus to the PCM.

The BCM detects the position of the Renegade Lighting Input and reports this over the PCI bus to the Cluster.

___________________________

Let me know if you have other questions.

Take care,
Joe
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Monday, March 11th, 2019 AT 4:40 PM
Tiny
CC49
  • MEMBER
HI, well I can't afford to go to dealer at this moment. Can you please tell me where to look for alarm system on my vehicle?
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Tuesday, March 19th, 2019 AT 8:21 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:
I hate to say it, but there isn't just one specific part that is the "alarm system". There are sensors, switches, the power-train control module, ignition module. The list goes on. You can't remove the PCM or ignition module to eliminate it because then nothing will work.

I'm sorry. I wish I had an easier answer for you.
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Wednesday, March 20th, 2019 AT 5:59 PM
Tiny
TONY KUNIS
  • MEMBER
Hi. Not sure if they have it here; https://www.jeepsareus.com, this is where I buy my Jeep parts. Maybe you can just order online and try to watch some videos on YouTube on how to do it. Will save you some cash.
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Wednesday, July 17th, 2019 AT 12:32 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi Tony:

Thanks for that info. I'm sure it will help.

Joe
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Wednesday, July 17th, 2019 AT 5:57 PM

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