The alarm system offers volumetric and perimeter protection against intrusion into the vehicle.A special control unit (integrated in the body computer) checks:
the state of the doors and lids, via switches in the handles (perimeter control)
the presence of a moving object inside the passenger compartment, by means of volumetric sensor (volumetric control)
an attempt to lift the vehicle or steal part of it (e.g. the wheels) through a tilt sensor
the condition of the system supply leads
the operation of the ignition switch.
The control unit is equipped with an autodiagnostic function which detects and memorizes faults and problems in the actual control and the system components; in addition, it checks the condition of the connecting cables and memorizes the number of activations and times the alarm has been operated.The control unit operating logic can be modified in order to satisfy the legal requirements which govern the use of alarm systems in the various markets.The alarm siren is located at the front, under a liner on the left of the engine compartment. The remote control sytem consists of a transmitter incorporated in the key and a receiver integrated in the body computer. In this case the key is read directly by the body computer which can check autonomously whether the key is recognized and authorized.The alarm system is switched on automatically the moment the doors are locked using the remote control. See E3040 CENTRAL LOCKINGWhen the doors are locked using the mechanical insert the alarm system is not switched on. The normal door locking signals are completed by the emission of a beep lasting a signal which signals that the alarm has been switched on.With the alarm system switched on, the LEDs in the front door panels flash red (deterrent function).If, when the alarm system is switched on, one or more of the doors or the boot is not properly shut or some of the alarm system modules are not recognized to be working or are faulty, a second beep is sounded to warn of the malfunction situation.The volumetric sensors check that there are no intrustions in the vehicle. They are located in the roof control unit: they consist of a transmitter and a receiver.The tilt sensor checks the position along the two axes, starts the check on the angular position of the vehicle which ends after 30 secs and is designed to produce a reference position.The alarm should be produced before an angle of 3° in relation to the initial position is reached.During the rest state, with the alarm system switched off and the ignition switched off, the volumetric and tilt protection systems can be manually excluded using special buttons so that the relevant sensors are not engaged.A variation in the volume identified by the waves inside the passenger compartment produces an alarm situation which is immediately signalled to the Body Computer control unit.The roof control unit sends the (volumetric) EXCLUS and (tilt) EXCLAINC message to the body computer via the A-BUS.