Fiat Brava Service Manual page 311

Electrical system
Fiat CODE
55.
INTRODUCTION
To increase protection against attempted theft, the cars are fitted with an electronic system for blocking
the engine, called "Fiat CODE", which is automatically activated when the ignition key is withdrawn.
The keys are fitted with a device which transmits a coded signal to the Fiat CODE control unit which,
only if it recognizes the signal, permits engine starting.
The Fiat CODE (immobilizer) system comprises:
- Fiat CODE control unit;
- electronic keys (three or four depending on the car model) containing a device which emits an elec­
tronic code;
- specific aerial on ignition switch;
- engine control unit with serial line for communication with the Fiat CODE control unit;
- Code Card with secret code for the emergency starting procedure;
- CODE warning light.
P4A056L01
The functions of the Fiat CODE control unit are:
- to recognize the introduction and rotation of a key in the ignition switch;
- to emit an electromagnetic field to give power to and activate the key's TRANSPONDER (code emit­
ter);
- to receive the secret code emitted from the key;
- to memorize a maximum of 8 keys with 8 electronic codes;
- to manage the checking/processing of the codes;
- to manage a single-wire bidirectional serial communication towards the engine control unit;
- to manage the lighting up of a special warning light;
- to recognize the connection with the Fiat/Lancia Tester and, for some versions, to prepare the use of
the serial line for the diagnosis function.
Bravo-Brava
5 8 Publication no. 506.670/01