Keys with transponder
The two keys contain the secret code used for programming the immobilizer and allowing the engine to be started.
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 is supplied with power by 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
Whenever the ignition key is turned from ON to OFF, the immobilizer system activates the engine start protection system.
When the engine is started and the key is turned from OFF to ON, the system generates the following signals:
- if the code is recognised, the protection system releases the engine lock. When you press the START button (C), the engine starts;
- if the code is not recognised, the EOBD diagnostics warning light (8) comes on. When you press switch (1) in position A "s", the word "Error" appears on the display, along with the error code denoting the type of IMMO error. In this case, turn the ignition key back to OFF and then to ON again. If the engine still does not start, contact your dealer.
Removal of the immobilizer
Set the ignition switch to OFF.
Disconnect the antenna wiring connector (A) from the main wiring loom.
Unscrew the two nuts (1) and remove the keyswitch cover (2) with the immobilizer antenna (3).
Remove the ties securing the immobilizer antenna wiring.
Undo the two nuts (1) securing the immobilizer antenna cover.
Remove the cover (2) and slide the antenna (3) out of the ignition switch.
Remove the special screws (6).
Remove the ignition switch (9) complete with the plate (8) from the frame.
Remove the plate (8) from the ignition switch (9).
Refitting the immobilizer
Insert the wire of the immobilizer antenna (3) in the plate (8).
Fit the plate to the ignition switch (9), routing the antenna wire through the slot (A) in the plate.
Apply the recommended threadlocker to the two special screws (6).
Fit the ignition switch (with the plate and antenna) to the frame (7) with the two special screws (6).
Tighten the screws fully to the specified torque (Frame torque settings).
Apply a drop of threadlocker inside the cover (2) at the points indicated in the figure.
Carefully install the antenna (3) inside the cover (2) and secure it with the two lugs (C) on the cover itself.
Fit the cover to the ignition switch, leading the antenna cable downwards.
Secure the cover with the two cap nuts (1).
Tighten the nuts to the specified torque (Frame torque settings).
