Rotation speed restricter

Rotation speed restricter

This strategy restricts the maximum speed which can be reached by the engine enabling the cut-off. There are two different cut-off thresholds:

• static restriction (the engine speed approaches the level slowly): maximum speed = 6670 rpm;
• dynamic restriction (the speed approaches the level rapidly): maximum speed = 6500 rpm;

Operation of electric fuel pump

The electric fuel pump is operated by the engine control unit by means of a relay.

The pump is stopped:

• if the engine speed goes below 50 rpm
• after a certain time (about 5 seconds) if the ignition key is in the ON position and the engine has not been started up (timed inhibition);
• if the inertia switch has intervened.

Operation of injectors

The operation of the injectors is the sequential, phased type. However, during cold starting, the injectors are operated in parallel up to a certain temperature.

The timing of the injectors varies according to the engine speed.

MANAGEMENT OF THE FIAT CODE ANTI-THEFT FUNCTION

The system is equipped with an anti-theft function. This function is achieved through the presence of a special (FIAT CODE) control unit, capable of conversing with the engine control unit, and an electronic key equipped with a special transmitter for sending a recognition code.

Each time the key is turned to the OFF position, the Fiat CODE system completely deactivates the engine control unit.

When the key is turned to the ON position the following operations take place in order:

1. the engine control unit (whose memory contains a secret code) sends the FIAT CODE control unit a request to send the secret code to deactivate the immobilization of the functions;
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;
3. the recognition of the secret code allows the immobilization of the engine control unit to be deactivated and normal operation resumed.

NOTE If a FIAT CODE anti-theft system is fitted, during the fault diagnosis, DO NOT CARRY OUT the test using another engine control unit. 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.