Sentry Key Immobilizer System (SKIS) Basic Checks

Sentry Key Immobilizer System Diagnosis:

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

SKIS Indicator Fails To Light During Bulb Test
If the Sentry Key Immobilizer System (SKIS) indicator in the instrument cluster fails to illuminate for about three seconds after the ignition switch is turned to the ON position (bulb test), perform the instrument cluster actuator test. (Refer to ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING - ACTUATOR TEST). If the bulb fails to operate during the actuator test, replace the bulb. If the SKIS indicator still fails to light during the bulb test, a wiring problem resulting in the loss of battery current or ground to the Sentry Key Immobilizer Module (SKIM) should be suspected, and the following procedure should be used for diagnosis. Refer to the appropriate wiring information.

NOTE: The following tests may not prove conclusive in the diagnosis of this system. The most reliable, efficient, and accurate means to diagnose the Sentry Key Immobilizer System requires the use of a DRB III scan tool. Refer to the appropriate diagnostic information.

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 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 continuity 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 DRB III scan 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 system 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 Module (BCM), or the message inputs and outputs between the SKIM and the Powertrain Control Module (PCM), a DRB III scan tool and the appropriate diagnostic information are required. Following are preliminary troubleshooting guidelines to be followed during diagnosis using a DRB III scan tool:
1. Using the DRB III scan 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 condition, this information may become invaluable to your diagnosis.
2. Using the DRB III scan 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 DRB III scan 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 information for the additional specific diagnostic steps.