223002954 - E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT - FUNCTIONAL DESCRIPTION

Functional description

Engine control unit M10 monitors and controls the electronic injection system. The supply for the engine control unit M10 is controlled by the ignition (15/54) at pin 23 of connector B by the line protected by fuse F16 of the engine compartment junction unit B01. The main injection relay R9 controls the entire system: it is supplied directly by the battery, via pin 1 of connector A, whilst the coil is supplied by the line protected by fuse F18; both are located in the engine compartment junction unit B01. This supply also reaches pin 50 connector B of M10.

The earth signal which energizes relay R9 which then sends the power suply arrives from pin 80 of connector B of the control unit M10:

• to pin 5 of connector B of the actual control unit, via the line from fuse F17 of B01;
• to pins 4 and 6 of connector B of the unit, via the line protected by fuse F22 of B01;
• to pin 5 connector A of the unit, to the speedometer sensor K84, to the EGR solenoid valve L30, to the diesel heating relay R19 of B01, to pin 3 connector A of the heater plugs control unit M15, via the line from fuse F11 of B01.

The (fuel pump) relay R10 is supplied by one of these main lines, namely by the line for fuse F21; both are housed in the engine compartment junction unit B01. An earth signal arrives from pin 75 of the control unit M10 which energizes the relay R10 which provides the supply for the electric fuel pump N40 which is earthed via the inertia switch I50 which, in the case of an impact, cuts off the circuit and prevents the supply of fuel which would be dangerous. The diesel preheating relay R19, located in the engine compartment junction unit B01 is supplied directly by the battery via the line protected by fuse F20. Pin 76 of connector B of control unit M10 receives the signal which energises the relay R19, which supplies and controls the operation of the diesel heating resistor K100: the thermal contact deactivates the system on completion of heating by means of the diesel temperature values which the engine control unit M010 detects at pins 61 and 13 connector B.The control unit M15, which manages the preheating of the heater plugs A40, is supplied directly by the line for the main relay R9 through the line protected by fuse F11 of the engne compartment junction unit B01 and controlled by the ignition by the line for fuse B37. It exchanges command and control signals with pins 70 and 74 connector B of M10 which controls the timing. Connector C is connected to the heater plugs A40.Pins 1, 2 and 3 of connector B 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 provides information concerning the engine speed by means of a frequency signal sent via pins 43 and 59 connector A of control unit M10. Both signals are weak and are therefore shielded.Timing sensor K47 is supplied from pin 21 of connector A of control unit M10. It receives a reference earth from pin 25 of the control unit M10 and sends it a signal of frequency corresponding to the timing of pin 56.The engine temperature sensor K45, receives a reference earth from pin 54 of connector A of the control unit M10 and supplies a signal proportional to the temperature of the engine coolant to pin 29.The air flow meter K41 receives an ignition controlled supply (INT) from pin 17 connector A of the junction unit under the dashboard B02 and receives a reference voltage, on the other hand, from pin 27 of M10. It is supplied by the control unit M10 from pin 40, and sends a signal proportional to the air flow to pin 14. K41 also contains an air temperature sensor which sends an air temperature signal to pin 10 of M10.The engine control unit receives, at pin 90 of connector B, the signal of the water-in-diesel filter sensor K31.Accelerator pedal K55 is fitted with two built-in potentiometers (a main one and a safety back-up). The first receives power and earth from pins 83 and 35 respectively of connector B of M10 and sends a corresponding signal to pin 65 of the same connector. The second receives power and earth from pins 15 and 32 respectively of connector B of M10 and sends a corresponding signal to pin 41 of connector B.The supercharging sensor K82 measures the engine supply pressure. It is supplied and receives a reference earth from pins 23 and 24 connector A of control unit M10. The signal is sent to pin 41 connector A of the control unit.The fuel pressure sensor K83 is responsible for providing the injection control unit with a feedback signal for governing pressure and injection duration. It receives power and a reference earth from pins 8 and 6 respectively of connector A of M10; it then sends the pressure signal to pin 38 connector A.The body computer M01 receives values from the speedometer sensor K84 at pin 17 of connector C.The fuel pressure regulator N77 has the task of keeping the value of the fuel pressure in the accumulator constant. The two control signals come from pins 4 and 34 of connector A of the control unit.The engine oil pressure sensor K30 sends an earth signal to pin 9 of connector A of the engine control unit M10.The EGR solenoid valve L30 controls the recirculation of the exhaust gases. It is supplied by the line protected by fuse F11 inside the engine compartment junction unit B01 and sends a signal to pin 15 connector A of the engine management control unit M10.Pin 93 of connector B of M10 receives the signal coming from the clutch pedal switch I31.Pins 92 and 68 connector B of the engine management control unit receive signals from the normally closed and normally open contacts of the brake pedal switch I03, respectively.The injectors N70 receive the opening enablement supply from pins 16 (cylinder 1 ), 17 (cylinder 2), 31 (cylinder 3) and 1 (cylinder 4) of connector A of M10.The engine control unit sends commands to the injectors from pins 47, 49, 48 and 46 of connector A, for cylinders 1, 2, 3 and 4 respectively.The supply for the body computer M01 is both controlled by the ignition and direct to pin 11 of connector E and pin A of connector C of the junction unit under the dashboard B02.There is a protective fuse F1 for the direct supply located in the engine compartment junction unit B01.These lines also supply the instrument panel, splitting inside the junction unit under the facia. The lines are protected by fuses F37 and F53.Pins 8 and 9 of connector D of the body computer are earthed.When the engine management control unit M10 detects a fault or the incorrect emission of exhaust gases, it sends a signal, via the CAN, to the instrument panel E50, via the body computer, which lights up the amber yellow ''injection system/EOBD failure'' warning light.The injection control unit M10 always exchanges information concerning the correct operation of the system via the CAN with the body computer M01 and with other network nodes: pins 58 and 59 connector B of the control unit and pins 36 and 37 connector C of the body computer.The control unit M10 supplies a diagnostic signal from pin 88 of connector B to pin 20 connector C of the body computer.The system autodiagnosis can be displayed by connecting the diagnostic equipment to connector B of the body computer (pin 7).The control unit M10 is connected to the air conditioning system via pins 26, 27, 28 and 79 of connector B. This allows the engine idling speed to be adjusted to increased engine loads 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 7 and 8 of connector B control the engagement of the relevant fan    See E5020 ENGINE COOLING.