Sentry Key Immobilizer System (SKIS)

Smart Key Immobilizer System (SKIS)
The SKIS is an immobilizer system designed to prevent unauthorized vehicle operation. The system consists of a Smart Key Immobilizer Module (SKIM) and ignition key(s) called Smart Key(s) which are equipped with a transponder chip. The SKIM communicates over the Chrysler Collision Detection (CCD)data bus network to the Powertrain Control Module (PCM), instrument cluster and/or the DRB scan tool.

When the ignition is turned to the Run/Start position, the SKIM produces a Radio Frequency (RF) via an antenna which is located around the ignition lock cylinder. The RF powers up the transponder chip inside the Smart Key. The transponder chip then emits a coded signal that is received by the SKIM antenna. If this coded signal is valid, the SKIM sends a "VALID KEY" message the PCM. If the first transponder signal is not valid, the SKIM will attempt four more times to receive a correct transponder signal. If a valid signal is not received, the SKIM stores a diagnostic trouble code and sends an "INVALID KEY" message to the PCM. Then the PCM will allow the engine to start for approximately two seconds and stall.


The SKIS includes two valid Smart Keys from the factory. If the customer wishes, additional uncoded Smart Key blanks are available. These blank keys must be cut to match a valid key, but the engine will not start unless the transponder chip inside the blank key is programmed to that particular vehicle.


The Smart Key Immobilizer System (SKIS) can be programmed to recognize a total of eight keys. For programming the Smart Key Transponder, refer to Maintenance and Service Information.


The SKIM also sends messages to the instrument cluster over the CCD bus to control the indicator lamp. The SKIM sends a message to the instrument cluster to turn the lamp on for about three seconds when the ignition is turned to the Run/Start position as a bulb test. If the indicator lamp 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 an invalid key is detected in the ignition key cylinder with the ignition switch in the Run/Start position, or when the SKIM has entered its customer key programming mode, the SKIM will flash the SKIS indicator lamp on and off.



Smart key Immobilizer Trouble Codes
Typically, modules have Diagnostic Trouble Codes that are referred to as either active or stored. In the case of the Smart Key Immobilizer Module, however, all codes are stored codes. The two various types of stored codes in the SKIM can be considered to be either current or pre-existing codes. If more than one code exists, diagnostic priority should be given to the current code(s). See TEST 1A to determine what codes are current and what ones are pre-existing. A current code indicates a malfunction that is current at the time of vehicle service. A pre-existing code indicates the malfunction is not currently present. If a malfunction is not detected after 80 ignition cycles, the code will automatically be erased.

Smart Key Immobilizer Module (SKIM) Replacement and System Initialization Process


The Smart Key Immobilizer Module (SKIM) replacement and system initialization process can be summarized by the following:


1. Obtain the vehicle's unique PIN number assigned to its original SKIM module from either the vehicle's invoice or from Chrysler's Customer Center.


2. With the DRB, select "Theft Alarm," "Skim," "Miscellaneous." Select "SKIM Module Replaced" function and the DRB will prompt you through the following steps.


3. Enter secured access mode using the unique 4 digit PIN number.


4. Program the vehicle's VIN number into the SKIM's memory.


5. Program the country code into the SKIM's memory (U.S.).


6. Transfer the vehicle's unique Secret Key data from the PCM. This process will require the SKIM module to be in secured access mode. The PIN number must be entered into the DRB before the SKIM will enter secured access mode. Once secured access mode is active, the SKIM will remain in that mode for 60 seconds.


7. Program all customer keys into the SKIM's memory. This requires that the SKIM be in secured access mode. The SKIM module will immediately exit secured access mode after each key is programmed.

Note: Secured access mode is not required to query the programmed status of the key.


Note 1: If a PCM is replaced, the unique Secret Key data must be transferred from the SKIM module to the PCM. This procedure requires the SKIM to be placed in secured access mode using the 4-digit PIN code.
Note 2: If three attempts are made to enter secured access mode using an incorrect PIN,

secured access mode will be locked out for one hour. To exit this locked out mode, turn the ignition to the Run position for one hour. (Ensure all accessories are turned off. Also monitor the battery state and connect a battery charger if necessary).


To program Smart Keys using the "customer programming" method, which requires two valid smart keys, refer to either the owner's or service manuals.