223002884 - E5032 METHANE ENGINE ELECTRONIC MANAGEMENT - FUNCTIONAL DESCRIPTION (BIPOWER)

Functional description

The engine control unit M10 monitors and controls the entire electronic ignition and injection system.The control unit M10 is supplied directly by the battery at pin 29 of connector A, via a line protected by fuse F18 of the engine bay control unit B01.The supply controlled by the ignition (15/54) reaches pin 47 of connector A of M10 from the line protected by fuse F16 of the engine compartment unit B01.

The main injection relay R9 of B01 controls the entire system: this is excited by a control signal received from pin 15 of connector A of control unit M10 and then sends power:

• to the injectors N70 and to the coils A30 and to the fuel pump N40, via the line protected by fuse F22 of B01;
• to the fuel vapour recovery solenoid L10 and the Lambda sensors K15 and K17 and ato the speedometer K84 via a line protected by fuse F11 of B01;
• via the line protected by fuse F22 of B01; The pump N40 is earthed via inertia switch I50 . In case of impact, this cuts off the circuit to prevent the danger of fuel delivery.

Pins 27 and 28 of connector A of M10 are earthed. The engine control unit M10 receives signals from the various sensors in order to monitor all engine service conditions. The rpm 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 timing sensor K47 is supplied from pin 68 of M10 . It receives a reference earth from pin 54 and sends a frequency signal corresponding to the timing at the pin for M10 .The integrated air temperature sensor K43 receives a reference earth from pin 54; it sends a signal corresponding to the intake air temperature 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 throttle position sensor K56 is supplied at 5 V from pin 60 and receives a reference earth from pin 54; it sends, through a potentiometer, a signal proportional to the degree of opening of the throttle to pin 76 of M10.The engine temperature sender unit 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 K50 provides information concerning the onset of detonation in the combustion chamber through frequency signals: it sends two signals to pins 6 (positive) and 70 (negative ) of M10 ; these signals are also suitably shielded (pin 63).The Lambda sensor at the pre-catalyzer K15 and the one at the catalyzer K17 provide the control unit M10 with information concerning the correct composition of the air/fuel mixture:The sensor K15 sends a signal to pin 20 of the control unit, whilst pin 9 provides a reference earth: the intensity of these two signals is extremely low and therefore they are appropriately shielded (pin 44). Sensor K15 is heated by a resistor in order to ensure it works efficiently even when cold; the resistance is supplied by relay R9 of B01; pin 1 of M10 provides the reference earth.The sensor K17 sends a signal to pin 24 of the control unit, whlst pin 12 provides the reference earth:the intensity of these two signals is extremely low and therefore they are appropriately shielded (pin 44). Probe K17 is heated by a resistor in order to ensure it works efficiently even when cold; the resistance is supplied by relay R9 of B01; pin 2 of M10 provides the reference earth.The control unit M10 receives the signal for the minimum engine oil pressure sensor K30 at pin 8 of connector A.The control unit M10 also controls the coil A30 through the signals for the coil primary winding, whilst the secondary winding sends the pulse 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 winding receives a signal to enable opening from relay R9 of B01 .The idle actuator N74 regulates the throttle 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 relay R9 of B01, is opened by the controlunit when the engine is loaded by a signal from pin 52 of M10.

The control unit M10 is connected via the CAN - pins 6 and 52 of connector A to the Body Computer M01 and the other nodes in the network: through this connection, it sends information concerning:

• system self-test, which can be used by connecting to connector B of M01;
• failure of the injection system and/or signalling of an incorrect exhaust gas emission - EOBD - (faults displayed via the special amber yellow warning light in the instrument panel E50);
• engine water temperature, which is sent to the instrument panel E50 which manages the relevant gauge and warning light;
• rpm, which is sent to the rev counter of the instrument panel E50 ;
• engine oil minimum pressure, which is sent to instrument panel E50 which manages the relevant warning light;

On the other hand it receives the speedometer signal, produced by sensor K84 , via the CAN.Self-diagnostic data can be read by connecting the unit to connector B of Body Computer M01 - pin 7; signals arrive from pin 25 of connector A of control unit M10 via the special diagnostic line.Methane injection control unit M19 processes the information coming from the sensors of the basic system, the information coming via the CAN from the control unit M10 (coolant temperature, air temperature) and the information coming from the sensors added for methane operation, in order to recognise the system''s operating conditions and generate the appropriate commands for the methane injectors.The control unit M10 is supplied directly from the battery at pin 1 by the line protected by fuse F18 of the engine compartment junction unit B01. The ignition controlled supply (INT) reaches pin 34 connector A from the line protected by fuse F35 of the junction unit under the dashboard B02. Pins 27, 28, 55, 61, 62 and 76 connector B of the control unit M19 are earthed. The CAN line goes from pins 23 and 38 connector A of M19 to the control unit M10, the Body Computer M01 and to the other network nodes

The main methane operation relay R10 for the engine compartment junction unit B01 is supplied directly from the battery by the line for fuse F21 of B01, whilst the supply for the coil is controlled by the ignition (15/54) by the line protected by fuse F16; it is energised by a control (earth) signal coming from pin 68 connector B of control unit M19, and consequently sends the supply:

• to the control unit M19, pins 59, 66 and 80;
• to coil of relay J26;
• to the methane injectors N72 .

The switching device H95 (which, in addition to the selector function, also includes the function of displaying the methane level and the operating mode selected), receives a supply and referenc earth from the methane control unit M19, pins 16 and 6; in the case of manual switching to petrol operation, it sends a signal to pin 47 of control unit M19. the effective methane operation signal leaves from pin 10 of M19.The methane pressure sensor K54, located on the regulation solenoid valve, receives a supply and reference earth from the methane control unit M19 - pins 16 and 6 - and sends a signal proportional to the pressure of the methane to the control unit M19 - pin 30; the latter sends a signal proportional to the level of the methane - from pin 60 connector B- to the switching device H95.The methane pressure and temperature sensor on the manifold K57 comprises a dual sensor, one resistive type (temperature) and one capactive type (pressure). It is located in the centre of the manifold where the methane injectors are fitted and receives a power supply and referenc earth from the methane control unit M19 - pins 16 and 6 - and sends a signal proportional to the pressure of the methane in the manifold and a signal relating to the temperature of the actual methane to pins 31 and 29 connector A, respectively, of control unit M19. Pins 54 and 74 connector B of the control unit M19 enable, in accordance with the control logic, the petrol or methane supply, consequently excluding the other. Pin 74 disables petrol operation sending an earth signal to the coil of relay J26 which is supplied by relay R9 of B01 through the line protected by fuse F22 of B01, whilst the coil is supplied by relay R10 of B01; when the relay J26 is energized, it cuts off the supply to the 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.Pin 54, on the other hand, enables methane operation - it sends an earth signal which energises methane operation relay J25: this is supplied by the line protected by the specific fuse B40, while the coil receives an ignition-dependent supply (INT) from the line protected by fuse F35 of the junction unit under the dashboard B02 ; it is energised by pin 54 of M19 and sends the supply to the methane cut-off solenoid L61 and to the three methane canister solenoids L60 (A- B - C) located on methane canisters (there are two canister solenoid valves - A and B - for the Doblò version).Solenoids L60 and L61 are all earthed via inertia switch I50. In case of impact, this cuts off the circuit to prevent the danger of fuel delivery. The control unit M19 receives some signals from the petrol system sensors.The rpm sensor K46, through a frequency signal sent to pins 51 (positive) and 52 (negative) connector A for the control unit M19, provides information concerning the engine speed: the intensity of these two signals is extremely low and therefore they are appropriately shielded. The timing sensor K47 is supplied by pin 68 of M10, and sends a signal of frequency corresponding to the timing to pin 12 of M19; a reference earth is sent to pin 11 of M19: these two signals are of very low intensity and are therefore suitably shielded.From pin 68 of M10 a reference supply is sent to the sensor K43 which returns a signal, to pin 44 of M19, proportional to the pressure of the intake air; a reference earth is sent to pin 33 of M19: these two signals are of extremely low intensity and are therefore suitably shielded.The throttle position sensor K56 is supplied at 5 V from pin 60 of M10; it sends, through a potentiometer, a signal proportional to the degree of opening of the throttle to pin 43 of M19; ; a reference earth is sent to pin 32 of M19: these two signals are of extremely low intensity and are therefore suitably shielded.The sensor K15 sends a signal to pin 46 of the control unit M19, while pin 35 receives the reference earth: these two signals are of extremely low intensity and are therefore suitably shielded.The control unit M10 controls - only in the case of petrol operation - the opening of the injectors N70 via special signals sent from pins 71, 71, 78 and 79 connector B. The injectors N70 receive an opening enablement supply from relay R9 of B01 .The control unit M19 controls - only in the case of methane operation - the opening of the injectors N72, via special signals sent from pins 64, 57, 63 and 56 connector B of M19.The methane injection control unit M019 exchanges information with the body computer M001 and other network nodes concerning the correct operation of the system via the CAN line, from pins 23 and 38 connector A, with pins 37 and 36 of connector C of the body computer.Self-diagnostic data can be read by connecting the unit to connector B of Body Computer M001 (pin 7); signals arrive from pin 3 of connector A of control unit M019 via the special diagnostic line.Control unit M10 is connected to the air conditioning system via pins 21, 35, 41 and 48 of connector A. This allows engine idling speed to be adjusted to increased engine load whenever the compressor is activated, or to turn off the compressor in the case of high speeds or high engine loads    See E6021 COMPRESSOR ENGAGEMENT.The control unit also controls the engine cooling system: pins 14 and 40 connector A control the engagement of the relevant fan    See E5020 ENGINE COOLING.