Vehicle Theft Alarm: Notes

WARNING: This page is about a different car, the 2015 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

The Body Control Module (BCM) (also known as the Common Body Controller/CBC) and the Radio Frequency Hub Module (RFHM) (also known as the RF Hub) are used on this vehicle to control and integrate many of the functions and features included in the Vehicle Theft Alarm (VTA). In the VTA system, the BCM receives inputs indicating the status of the door ajar switches, the ignition, the deck lid ajar switch and the power lock switches. In vehicles built for certain export markets where it is required, the hood ajar switch and the Intrusion Transceiver Module (ITM) also provide inputs to the BCM.

The BCM processes the information from all of these inputs and sends the appropriate electronic messages to other electronic modules over the Controller Area Network (CAN) data bus. The BCM internally controls the output to the hazard warning lamps and sends a control output to energize or de-energize the horn relay. The RFHM relays the status of the ignition and all RF commands received from the Remote Keyless Entry (RKE) buttons of the FOB with Integrated Key (FOBIK) to other electronic modules over the CAN data bus.

The hard wired circuits between the components related to the VTA system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin out information, and location views for the various wire harness connectors, splices, and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the VTA system or the electronic controls and communication between modules and devices that provide some features of the VTA system. The most reliable, efficient and accurate means to diagnose the VTA system or the electronic controls and communication related to VTA system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Following are paragraphs that briefly describe the operation of each of the VTA features. See the owner's manual in the vehicle glove box for arming and disarming procedures, use and operation of the VTA.