Aerial For Electronic Key (Code)

To increase protection against theft attempts, an engine immobilizer system known as ALFA ROMEO CODE is used. The CODE system only allows the engine to be started by means of the engine management control unit after a password, memorized previously, is received.

The code used in the dialogue, that takes place via an aerial coaxial to the ignition switch, varies each time the engine is started (rolling code): therefore the code cannot be reproduced even using electronic scanners.

The Code system control unit is incorporated in the Body Computer and also includes:

• C CAN line for dialogue with the Body Computer and the engine management control unit;
• remote control containing a transponder with a password;
• an aerial that reads the code contained in the transponder;
• engine management control unit.

The CODE allows the start of the engine management by the engine management control unit by means of a coded dialogue between the Body Computer and the engine management control unit during the stage prior to starting. After the key is turned to the ON position, the engine control unit sends a code request to the Body Computer which only responds after having recognised (through the aerial) a known transponder in the ignition switch. If the secret code in the reply is valid, the engine management control unit continues with the regular engine management activities, allowing the engine to be started. If the transponder is not recognised, engine start-up is inhibited. Operation of the CODE is guaranteed if any of the other Body Computer functions are not working correctly. The function involves the display of the status through the "vehicle protection system" warning light in the instrument panel and connected via the CAN switching on.

FUNCTIONAL DESCRIPTION 

• The CODE unit is located inside the Body Computer M001 and receives a direct supply - connector A - from the battery via the line protected by maxifuse F01 of the engine compartment junction unit B001.
• The Body Computer M001 receives an ignition-controlled power supply (INT) at pin 11 of connector E: this signal is used, amongst other things, to "wake up the network".
• The CODE device aerial P091 is connected, via two cables to the CODE unit of Body Computer M001, to pins 1 and 2 of connector F; the aerial is positioned coaxially on the ignition switch in order to detect the key being inserted and turned.
• The key recognition dialogue and the exchange of codes between the Body Computer M001 and the engine management control unit M010 takes place through CAN-C.
• The Body Computer M001 is connected, through the CAN line, to the instrument panel E050 to manage the "vehicle protection" warning.