Component Tests and General Diagnostics

SENTRY KEY IMMOBILIZER SYSTEM

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS,FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE OCCUPANT PERSONAL INJURY OR DEATH.

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 (SKIS) involves the use of a DRB III(R) scan tool and the proper Power-train Diagnostic Procedures manual.

The Sentry Key Immobilizer System (SKIS) and the Programmable Communication Interface (PCI) bus network should be diagnosed using a DRB III(R) scan tool. The DRB III(R) will allow confirmation that the PCI bus is functional, that the Sentry Key Immobilizer Module (SKIM) is placing the proper messages on the PCI bus, and that the Powertrain Control Module (PCM) and the instrument cluster are receiving the PCI bus messages. Refer to the proper Powertrain Diagnostic Procedures manual. Refer to Wiring Diagrams for complete circuit descriptions and diagrams.

1. Check the fuses in the fuse block. If OK, go to Step 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.

Battery Negative Cable - Remove/Install:

2. Disconnect and isolate the battery negative cable. Unplug the wire harness connector at the SKIM. Check for continuity between the ground circuit cavity of the SKIM wire harness connector and a good ground. There should be continuity. If OK, go to Step 3. If not OK, repair the open circuit to ground as required.

3. Connect the battery negative cable. Check for battery voltage at the fused B(+) circuit cavity of the SKIM wire harness connector. If OK, go to Step 4. If not OK, repair the open circuit to the fuse in the fuse block as required.
4. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run/start) circuit cavity of the SKIM wire harness connector. If OK, use a DRB III(R) scan tool and the proper Powertrain Diagnostic Procedures manual to complete the diagnosis of the SKIS. If not OK, repair the open circuit to the fuse in the fuse block as required.

GENERAL TROUBLESHOOTING TIPS
1. Using a DRB III� scan tool, read and record the faults as they exist in the module when you first start your analysis of the vehicle. It is important to document these faults because the SKIM does not differentiate between historical faults (those faults that occurred in the past) and active faults (those faults that are present now). If this problem turns out to be an intermittent condition, this information may become very valuable to your analysis.
2. Using a DRB III(R) scan tool, erase the faults in the Sentry Key Immobilizer Module (SKIM).
3. Turn the ignition off and back on again.
4. Using a DRB III(R) scan tool, read the faults now listed in the Sentry Key Immobilizer Module (SKIM).
5. Using the fault information you now have, refer to the proper Powertrain Diagnostic Procedures manual for additional specific steps.