Sentry Key Immobilizer System

The Sentry Key Immobilizer System (SKIS) is factory-installed standard equipment on this vehicle. The SKIS provides passive vehicle protection, immobilizing the vehicle by preventing the engine from operating unless a valid electronically encoded key is detected in the ignition lock cylinder. Vehicles with this equipment can be readily identified by the illumination of the security indicator in the Instrument Panel Cluster (IPC) for about three seconds after the ignition switch is turned to the On position as a SKIS bulb test.

The functions and features of the SKIS are all integral to the Body Control Module (BCM) in this vehicle. The BCM is located in the instrument panel, outboard of the steering column.

The SKIS includes the following major components described in further detail elsewhere in this service information:

• Body Control Module  - The BCM is located within the instrument panel outboard of the steering column. Refer to MODULE, BODY CONTROL (BCM), DESCRIPTION .
• Powertrain Control Module  - The Powertrain Control Module (PCM) is located in the engine compartment and provides the SKIS engine control logic.
• Security Indicator  - A security indicator is integral to the IPC. Refer to DESCRIPTION .
• Sentry Key Immobilizer Antenna  - A antenna ring located around the ignition switch lock cylinder's circumference and concealed beneath the steering column shrouds.
• Sentry Key Transponder  - The Sentry Key transponder microchip is located on the circuit board within the Remote Keyless Entry (RKE) transmitter of each ignition key.

The BCM cannot be adjusted or repaired but is flash update capable. If ineffective or damaged, the entire BCM unit must be replaced. Refer to MODULE, BODY CONTROL (BCM), DESCRIPTION .

Except for the Sentry Key transponders, which rely upon Radio Frequency (RF) communication, hardwired circuitry connects the SKIS components to the vehicle's electrical system. These hardwired circuits are integral to several wire harnesses routed throughout the vehicle and retained by many different methods. These circuits are connected to the vehicle electrical system and the SKIS components with a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes appropriate SYSTEM WIRING DIAGRAMS, proper wire and connector repair procedures, further details on wire harness routing and retention, and pinout and location views for the various wire harness connectors, splices, and grounds.