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The immobilizer allows the vehicle to be started only if the rider uses the special ignition key which sends the identification code to a decoder housed in the instrument panel. The transmission-receiving system is composed of a TRANSPONDER housed in the ignition key heads and an antenna in the vicinity of the ignition switch.
Keys with transponder
The two keys contain the secret code that is used for programming the immobilizer system and which enables engine starting.
The transponder is fitted inside the key grip and consists of a power supply circuit, a ROM (Read-Only Memory) and a transmission circuit. The transponder receives its power from the magnetic field generated by the antenna, which is enabled as soon as the instrument panel is switched on. Since the transponder is very compact and needs no external battery power supply, it is moulded permanently into the key grip.
 Warning
The circuits in the key grips are not shockproof and may therefore be damaged by violent impact.
Immobilizer antenna
The antenna consists of a plastic-coated copper coil connected to a cable that is terminated with a connector.
The antenna (A) is fitted onto the cover (B) of the ignition lock, which is specifically modified for the purpose to create a seat in which the antenna is inserted and engaged.
Immobilizer operating principle
At key-on (switching on the instrument panel by turning the key) the decoder (incorporated in the instrument panel) activates the antenna, which emits an electromagnetic field that serves to power the transponder in the key grip. The transponder responds by transmitting the code that is stored on its internal ROM memory, and which is picked up by the antenna and relayed to the decoder. Here the transponder code is compared to a second code. If the outcome of the comparison is positive, engine starting is enabled.
Warning light signals and immobilizer indications
When the ignition key is turned from ON to OFF, the immobilizer system activates the engine lock. When the ignition key is turned from OFF to ON to start the engine:
1) if the code is recognised, the protection system releases the engine lock. When you press the START button (C), the engine starts;
2) if the code is not recognised, the diagnostics warning light (10) comes on and if, when you press switch (2) “t”, the “Error IMMO” message appears on the display, this indicates that the code has not been recognised. In this case, turn the ignition key back to OFF and then to ON again. If the engine still does not start, try again with the other black key. If the engine still does not start, proceed with fault diagnosis.
Removal of the immobilizer and ignition switch
Set the ignition switch to OFF.
Disconnect the immobilizer antenna connector (A) and ignition switch connector (B).
Unscrew the nuts (1) securing the ignition switch cover (2) and remove it along with the immobilizer antenna.
Unscrew the bolts (3) and remove the igntiion switch (4) from the frame.
Refitting the immobilizer and ignition switch
Apply the recommended threadlocker to the bolts (3).
Locate the igntion switch (4) on the frame and tighten the bolts (3) to the specified torque (Sect. C 3, Frame torque settings).
Apply a drop of Loctite to the inside of cover (2).
Carefully install the antenna (3) inside the cover (2), securing it with the two lugs (C) on the cover itself.
Fit the cover to the ignition switch, leading the antenna cable downwards.
Tighten the nuts (1) to the specified torque (Sect. C 3, Frame torque settings).
Disconnect the wiring connector of the ignition switch (B) and the connector of the antenna immobilizer (A) from the main wiring loom.