Electronic control unit

ELECTRONIC CONTROL UNIT

The electronic control unit is a minicomputer which analyzes the data for the engine operating conditions which is transmitted by the sensors; it processes the signals arriving from the peripheral sensors and, with the aid of programmed diagrams, it controls the impulses for the injector and the moment of ignition.

It is connected to the system by means of a 35 pole socket and is protected from false polarity and short circuits.

The electronic control unit can detect the inefficiency of the various sensors and replace the information which is incorrect or has not been received with figures taken from areas of the memory in order to ensure the operation of the engine even in emergency conditions; in addition, it is also equipped with a autodiagnostic strategy for both the input and output sensors with a specific memory for detecting any problems which are then transmitted during the fault diagnosis.

Therefore, with the aid of the F/L Tester connected to the system, it is possible to automatically diagnose or display (display) any errors which may be present in the memory.

There is a function in the control unit which when the ignition is turned to the OFF position supplies the charcoal filter solenoid valve for about 15 seconds to prevent these vapours from reaching the inlet and possibly causing the phenomenon of self-ignition.

Control unit functions

The control unit performs the following functions:

• a. Metering the fuel
• b. Checking the electric fuel pump supply
• c. Starting
• d. Acceleration and full power
• e. Deceleration and cut-off
• f. Lambda adjustment
• g. Autodiagnosis
• h. Active diagnosis
• i. Coded anti-theft device

The control unit is also the self-adjusting type. This function makes it possible for the system to recognize and, by means of appropriate strategies, adapt to the various changes (from atmospheric ones to those stemming from the wear of components) which cause result in irregular engine operation.

The control unit uses four different parameters for its self-adjustment which allow it to take into account variations in atmospheric pressure, seepage downstream of the butterfly and variations in the injector and the position of the butterfly during starting.

The updating of the parameters cannot be carried out during the transitory stages of enrichment and cut-off. This function, compensating for the inevitable differences due to wear or to production tolerances of components which may have been replaced, makes it possible to achieve the best possible results without the need for regulation and checking operations.