223002941 - 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 58 by the line protected by fuse F16 of the engine compartment junction unit B01 .

The main injection relay R9 housed in junction unit B01 controls the entire system: it is energized by a control signal (earth) received from pin 13 of control unit M10 and then sends power::

  • to pin 4 of the actual control unit, via the line from fuse F17 of B01.
  • to pin 5 of the actual control unit, via the line from fuse F22 of B01.
  • to the water in the diesel filter sensor K31 , to the air flow meter K41, to the solenoid valves L30 , L35 and L62 , t the control unit M15 , via the line from fuse F11 of B01 .
The fuel pump relay R10 of B01 is supplied from the line of fuse F21 of B01 . It is energized by a control signal (earth) from pin 24 of control unit M10 and supplies power to fuel pump N40 , which is earthed through the inertia switch I50 , which cuts off the circuit in the case of a crash and so prevents the dangerous spilling of fuel.Pins 1, 2 and 3 of M10 are earthed.The diesel pre-heating relay R19 of B01 is supplied by the line for fuse F20 of B01 .It is energized by a control signal (earth) coming from pin 23 of the control unit M10 and supplies power to the diesel heating resistance O20 .Control unit M15 , responsible for controlling preheating of heater plugs A40 , is supplied directly by the battery via a line protected by fuse F37 . It is controlled, via connector A, by the line for fuse F11 of B01 and exchanges control signals with pins 22 and 62 of M10 which controls the timing. Connector C is connected to the heater plugs A40.

The engine management 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 through an alternating signal sent to pin 100 of the control unit M10 . It receives an earth signal from pin 99 of the control unit. Both signals are suitably screened (pin 101);
  • Timing sensor K47 is supplied by pin 102 of M10 . It receives a reference earth from pin 104 of the control unit M10 and sends it a signal of frequency corresponding to the timing of pin 103.
  • The engine temperature sensor K45 , receives a reference earth from pin 85 of the control unit M10 and supplies a signal proportional to the temperature of the engine coolant to pin 84.
  • The air flow meter K41 receives a general supply from the line for fuse 11 of B01 and a reference voltage from pin 88 of M10 . It is supplied by the control unit from pin 97 of M10 , and sends to pin 89 a signal proportional to the air flow. K41 also contains an air temperature sensor which sends an air temperature signal to pin 86 of M10 .
  • 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 78 and 76 respectively of M10 and sends a corresponding signal to pin 77. The second receives power and earth from pins 81 and 79 respectively of M10 and sends the signal to pin 80.
  • The fuel temperature sensor K81 measures the temperature of the diesel entering. It receives a reference earth from pin 83 of M10 and sends the fuel temperature signal to pin 82.
  • The supercharging sensor K82 measures the engine supply pressure. It is supplied by pin 93 of M10 and receives a reference earth from pin 95. The signal is sent to in 94 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 the power and reference earth from pins 90 and 92 of M10 ; it then sends the pressure signal to pin 91.
  • 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 108 and 109 of the control unit M10 .
  • The EGR solenoid L30 controls exhaust gas recirculation. It is supplied by the line protected by fuse F11 and from pin 16 of the engine control unit M10 .
  • The solenoid valve on the throttle casing L62 shutters and closes the throttle, for example when the engine is switched off; it is supplied by the line for fuse F11 of B01 and is controlled by a signal for pin 15 of M10 .
Pin 61 of M10 receives an earth signal coming from the clutch switch I31 .The engine management control unit receives the signals from the normally closed and normally open contacts of the brake pedal switch I30 at pins 54 and 59.The injectors N70 receive the opening go ahead supply from pins 117 (cylinders 1 and 2) and 118 (cylinders 3 and 4) of M10 .The engine control unit sends commands to the injectors N70 from pins 119, 120, 121 and 114 of connector A for cylinders 1, 2, 3 and 4, respectively.The control unit M10 receives the minimum engine oil pressure sensor K30 signal at pin 98.The water in diesel filter sensor K31 is supplied by the line of fuse F11 of B01 and sends a corresponding signal to pin 105 of the engine management control unit.

The control unit M10 is connected, via the CAN - pin 6 and 7 - and via the diagnostic serial line - pin 48 - to the body computer M01 (pins 36, 37 and 20 of connector C) and to the other network nodes: it receives information concerning the following via the latter:

  • system autodiagnosis, which can be displayed by connecting the diagnostic equipment to connector B of M01; the injection system failure and/or the signalling of incorrect exhaust gas emissions - 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;
  • heater plugs pre-heating, which is sent to the instrument panel E50 which manages the appropriate warning light.
The control unit receives the speedometer signal, produced by the sensor K84 , via the CAN.The control unit M10 is connected to the air conditioning system through pins 18, 51, 52 and 60. 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 19 and 20 control the engagement of the relevant fan    See E5020 ENGINE COOLING.