Vehicle Theft Security Siren - Operation - Export

OPERATION

The microprocessor within the alarm siren module provides the siren unit features and functions based upon internal programming and electronic arm and disarm messages received from the intrusion module over a dedicated serial bus communication circuit. The siren module receives battery voltage on a fused B(+) circuit through a fuse in the Totally Integrated Power Module (TIPM), and receives a path to ground through a ground circuit in the wire harness. These connections allow the siren to remain operational, regardless of the ignition switch position.

When the premium version of the Vehicle Theft Alarm (VTA) is armed, the siren module continuously monitors electronic message inputs from the intrusion module to sound its internal siren. While armed, the siren also enters its auto-detect mode. While in the auto-detect mode, if the siren module detects that its power supply or communication circuits are being tampered with or have been sabotaged, it will sound an audible alarm and continue to operate through an on-board backup battery. If the siren module is in its disarmed mode when its power supply or communication circuits are interrupted, the siren will not sound.

After a battery disconnect, siren disconnect or siren replacement, the siren will automatically enter into a 14 hour charge cycle. Siren charging is independent of ignition key position and will draw approximately 20 mA throughout the cycle. Thereafter, the siren will periodically enter the charge cycle drawing an average of 1 mA to maintain the internal battery.

The siren will self-detect problems with its internal and external power supply and communication circuits, then send electronic messages indicating the problem to the intrusion module upon receiving an arm or disarm request. The intrusion module will store a Diagnostic Trouble Code (DTC) for any detected alarm siren module fault. The DTC can then be retrieved with a diagnostic scan tool through the 16-way Data Link Connector (DLC) located under the driver side lower edge of the instrument panel over the Controller Area Network (CAN) data bus.

To diagnose the siren, the intrusion module, the CAN data bus communication line, and the electronic message inputs to and outputs from the siren requires the use of a diagnostic scan tool and the appropriate diagnostic information.