Sentry Key Immobilizer System: Description

The purpose of the vehicle's Immobilizer system is to disable engine starting. Starting is only enabled if all components that make up the immobilizer system are able to each perform, on its own, the phases for authenticating the secret codes stored in them. The immobilizer system components are:

• Body Control Module  - The BCM is concealed within the passenger side of the instrument panel. Refer to MODULE, BODY CONTROL (BCM), DESCRIPTION AND OPERATION .
• Powertrain Control Module  - The Powertrain Control Module (PCM) is located in the engine compartment and provides the immobilizer engine control logic. Refer to MODULE, POWERTRAIN CONTROL (PCM), DESCRIPTION AND OPERATION .
• Radio Frequency Hub  - The Radio Frequency Hub (RFH) is located in the center of the instrument panel below the instrument panel pad and behind the radio display. Refer to MODULE, RADIO FREQUENCY (RF HUB), DESCRIPTION AND OPERATION .
• 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 or within each FOBIK. Refer to KEY, TRANSPONDER, DESCRIPTION AND OPERATION .
• Electric Steering Lock Module  - The Electric Steering Lock (ESL) module is located on the top of the steering column. Refer to MODULE, ELECTRONIC STEERING LOCK (ESL), DESCRIPTION AND OPERATION .

The BCM, the PCM and the RFH each contain a microcontroller and programming that allow them to communicate with each other and other electronic modules in the vehicle using the Controller Area Network (CAN) data bus. In addition, the Start/Stop button and the RFH communicate with each other using a Local Interface Network (LIN) data bus. Refer to COMMUNICATION, DESCRIPTION AND OPERATION .

Except for the key transponders, which rely upon Radio Frequency (RF) communication, hardwired circuitry connects the various immobilizer components to the electrical system of the vehicle. These hardwired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the immobilizer components through the use of 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 wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin out and location views for the various wire harness connectors, splices and grounds.