Vehicle Theft Security System: Notes

The ElectroMechanical Instrument Cluster (EMIC) is used on this vehicle to control and integrate many of the functions and features included in the VEHICLE THEFT SECURITY SYSTEM (VTSS). The EMIC is also sometimes referred to as the Cab Compartment Node (CCN). In the VTSS, the EMIC receives inputs indicating the status of the door ajar switches and the ignition switch. The EMIC processes the information from all of these inputs, internally controls the security indicator as appropriate, and sends electronic messages to the Front Control Module (FCM) over the Controller Area Network (CAN) data bus. The FCM internally controls the output to the hazard warning lamps and sends a control output to energize or de-energize the horn relay as appropriate. The hard wired circuits between components related to the VTSS may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate SYSTEM WIRING DIAGRAMS article. The wiring information includes wiring diagrams, proper wire and connector repair procedures, 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 VTSS or the electronic controls or communication between modules and devices that provide some features of the VTSS. The most reliable, efficient, and accurate means to diagnose the VTSS or the electronic controls and communication related to VTSS operation requires the use of a diagnostic scan tool  . See the VEHICLE THEFT SECURITY SYSTEM  menu item on the scan tool. Refer to the appropriate diagnostic information.

Following are paragraphs describing the operation of each of the VTSS features. See the owner's manual for more information on the features, use and operation of the VTSS.