Self-Adjustment Of The System; Autodiagnosis; Connection With The Engine Immobilizer Device (Fiat Code) - Fiat Bravo Service Manual

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Self-adjustment of the system

The control unit is equipped with a self-adjustment function w h i c h is designed to recognize the
changes w h i c h take place in the engine due to the bedding in processes over a period of time and the
ageing of b o t h the components and the engine itself.
These changes are memorized in the form of modifications to the basic map and are designed to adapt
the operation of the system to the gradual alterations to the engine and components compared w i t h
when new.
This adjustment function also makes it possible to compensate for inevitable differences (due to pro-
duction tolerances) in any components w h i c h are replaced. This means that all vehicles can have the
best results without special adjustment and control operations.

Autodiagnosis

The ME 3.1 injection/ignition system is also equipped w i t h an " a u t o d i a g n o s t i c " function w h i c h
memorizes any faults in the sensors and actuators, making it easier to identify and correct them. A fault
is signalled by the warning light in the instrument panel coming on.
Connection with the engine immobilizer device (Fiat C O D E )
To increase protection against theft attempts, the vehicle has been equipped w i t h an engine immobilizer
system (Fiat CODE) w h i c h only allows the injection/ignition control unit to be activated by an electron-
ic code.
Each time the key is turned to the OFF position, the FIAT CODE system completely deactivates the i n -
jection/ignition control unit.
If the ignition key is turned from OFF t o O N , the following operations take place in order:
1. The injection/ignition control unit sends the Fiat CODE control unit a request for a secret code in or-
der to deactivate the immobilizer function.
2. The Fiat CODE control unit responds by only sending the secret code after having, in turn, received
the recognition code transmitted by the ignition key, w h i c h contains a special transponder.
3. The recognition of the secret code allows the de-activation of the immobilizer function and the injec-
tion/ignition control unit can activate the normal system management programme.
A special t w o - w a y serial line allows the exchange of data between the injection/ignition control unit
and the Fiat CODE control unit.
If there is a fault w i t h the Fiat CODE system, the enginecan be started up using the emergency proce-
dure.
Given the presence of the Fiat CODE system D O N O T carry out tests using another injec-
tion/ignition control unit during the fault diagnosis and I or operating checks. In such a case, the
Fiat CODE control unit would transfer the (unrecognized) recognition code to the test control
unit which could then no longer be used on other vehicles.
Copyright by Fiat Auto
E n g i n e
Fuel system
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