E5030 PETROL ENGINE ELECTRONIC MANAGEMENT - FUNCTIONAL DESCRIPTION - Fiat - MULTIPLA - eLearn

2892619 - E5030 PETROL ENGINE ELECTRONIC MANAGEMENT - Functional description

Functional description

The engine control unit M10 monitors and controls the entire electronic ignition and injection system. The control unit is supplied directly by the battery - at pin 29 - by the line for the maxifuse EFI of B5, through the line protected by fuse B35. The supply controlled by the ignition (15/54) reaches pin 47 from the line protected by fuse B25. Pins 27 and 28 of the control unit M10 are earthed.

The main relay J10 is supplied directly by the battery from the line for the maxifuse EFI of B5.whilst the coil supply is controlled by the ignition (15/54) from the line protected by fuse B25; it is energized by an (earth) signal coming from pin 15 of the control unit M10 (safety signal which enables the fuel pump) and, as a result, sends the supply:

to the injector N70 ;
to the coil A30 ;
to the Lambda sensor heater, through the line protected by fuse B36 ;
to the vapour recovery solenoid valve L10 through the line protected by fuse B36 ;
to the electric fuel pump N40 ;

The electric fuel pump N40 is earthed through the inertia switch I50 which, in the case of an impact, cuts off the circuit and stops the dangerous supply of fuel. The control unit M10 receives signals from the various sensors in order to monitor all engine service conditions. The sensor K46, through a frequency signal sent to pins 53 (positive) and 67 (negative) for the control unit M10, provides information concerning the engine speed: the intensity of these two signals is extremely low and therefore they are appropriately shielded (pin 77). The integrated air temperature sensor K43 receives a reference earth from pin 54; it sends a signal corresponding to the temperature of the intake air to pin 55 of the control unit. From pin 68 of M10 a reference supply is sent to the sensor K43 which restores a signal, at pin 75, proportional to the pressure of the intake air. The butterfly position sensor K56 receives a 5 V supply from pin 60 and receives a reference earth from pin 54; it sends a signal, through a potentiometer, which is proportional to the opening of the butterfly, to pin 76 of M10. The engine temperature sensor K45, receives a reference earth from pin 54 of the control unit M10 and supplies a signal proportional to the temperature of the engine coolant to pin 62 of the control unit. The detonation sensor provides information concerning the onset of detonation in the combustion chamber through frequency signals: it sends two signals to pins 56 (positive) and 70 (negative ) of M10; these signals are also suitably shielded (pin 63). The heated Lambda sensor K40 provides the control unit M10 with information concerning the correct composition of the air/fuel mixture: the signal is sent to pin 20 of the control unit, whilst pin 9 provides the reference earth: the intensity of these two signals is extremely low and therefore they are appropriately shielded (pin 44). The sensor K40 is heated by a resistance to ensure correct operation, even when cold; the resistance is supplied by the main relay J10 through the line protected by fuse B36. The control unit M10 controls the opening of the injectors N70 via special signals sent from pins 71, 78 and 79. Injectors N70 receive a power supply to enable opening from main relay J10. The control unit M10 also controls the coil A30 through the signals for the coil primary winding, whilst the secondary winding sends the impulse to the spark plugs: from pin 59 for the pair of cylinders 1 & 4 and from pin 66 for cylinders 2 & 3. The coil A30 primary windings receive a signal to enable opening from main relay J10. The idle actuator N74 regulates the butterfly by-pass line. It is controlled by the control unit M10 through the signals from pins 57, 58, 64 and 65. Fuel vapour recovery solenoid L10 allows fuel vapours to pass through to the engine intake where they join the mixture entering the combustion chamber. The valve L10, supplied by the main relay J10, is opened by the control unit when the engine is loaded by a signal from pin 52 of M10. The control unit M10 is connected with the CODE control unit M20 through the special serial line from pin 13; this way, if the CODE control unit does not detect a correct code, it does not give the go ahead and the engine is not started up. ( See E7010 CODE ). The control unit is equipped with an auto-diagnostic system which can be used by connecting the unit to the connetor R10: it receives signals from pin 25 from the control unit M10 through the special diagnostic line. The auto-diagnostic system also produces the signal for the "injection failure" warning light in the instrument E50, which comes from pin 26 of the control unit M10. If the engine temperature is high, the control unit causes the relevant warning light in the instrument panel E50 to come on (signal from pin 17 of M10). The speedometer signal (vehicle speed) reaches pin 50 of the control unit M10 ( See E4010 INSTRUMENT PANEL ). The control unit M10 is connected with the air conditioning system through pins 41 and 48. This makes it possible to adjust the engine idle speed as the load increases each time the compressor is switched on or to switch off the compressor in the case of high engine speed or load conditions ( See E6021 COMPRESSOR ENGAGEMENT ). The control unit also controls the engine cooling system: pins 14, 35 and 40 control the engagement of the relevant fan ( See E5020 ENGINE COOLING ).