Pressure pump electric control

Description 1060G

1.3 JTD

Injection control unit (MJD - 6JF Magneti Marelli common rail)

It is fitted in the engine compartment.

The control unit is the 'flash EPROM type, i.e. reprogrammable from the outside without intervening on the hardware.

The injection control unit integrates the absolute pressure sensor.

PIN-OUT

CONNECTOR A

1, Cylinder 4 injector positive

2, Not connected

3, Not connected

4, Fuel pressure regulator positive

5, Positive from main relay

6, Fuel pressure sensor negative

7, Not connected

8, Fuel pressure sensor positive

9, Insufficient engine oil pressure sensor signal

10, Flow meter air temperature signal

11, Not connected

12, Not connected

13, Not connected

14, Flow meter air flow signal

15, E.G.R. solenoid negative

16, Cylinder 1 injector negative

17, Cylinder 2 injector positive

18, Not connected

19, Not connected

20, Not connected

21, Timing sensor negative

22, Not connected

23, Intake air temperature and supercharging pressure sensor positive

24, Intake air temperature and supercharging pressure sensor negative

25, Timing sensor positive

26, Not connected

27, Flow meter negative

28, Not connected

29, Engine coolant temperature sensor earth

30, Not connected

31, Cylinder 3 injector negative

32, Not connected

33, Not connected

34, Fuel pressure regulator negative

35, Not connected

36, Not connected

37, Not connected

38, Fuel pressure sensor signal

39, Not connected

40, Flow meter positive

41, Turbo pressure signal

42, Not connected

43, Engine rpm positive

44, Not connected

45, Not connected

46, Cylinder 4 injector negative

47, Cylinder 1 injector negative

48, Cylinder 3 injector negative

49, Cylinder 2 injector negative

50, Not connected

51, Not connected

52, Not connected

53, Not connected

54, Engine coolant temperature sensor signal

55, Not connected

56, Timing sensor signal

57, Not connected

58, Not connected

59, Rpm sensor negative

60, Not connected

CONNECTOR B

1, Control unit power earth

2, Control unit power earth

3, Control unit power earth

4, Control unit 12V supply

5, Control unit 12V supply

6, Control unit 12V supply

7, Fan 1 control (-)

8, Fan 2 control (-)

9, Not connected

10, Air conditioner compressor linear sensor negative

11, Not connected

12, Not connected

13, Fuel temperature sensor earth

14, Not connected

15, Track 1 positive on accelerator pedal potentiometer

16, Not connected

17, Not connected

18, Not connected

19, Not connected

20, Not connected

21, Not connected

22, Not connected

23, Ignition-controlled supply

24, Not connected

25, Not connected

26, Not connected

27, Not connected

28, Request to engage cliimate control from control button

29, Engine rpm signal for robotised gearbox

30, Not connected

31, Not connected

32, Track 2 negative on accelerator potentiometer

33, Not connected

34, Not connected

35, Track 1 negative on accelerator potentiometer

36, Not connected

37, Air conditioner compressor linear sensor positive

38, Not connected

39, Not connected

40, High speed CAN 1 line

41, Accelerator potentiometer track 2 signal

42, Not connected

43, Not connected

44, Not connected

45, Not connected

46, Not connected

47, Not connected

48, Not connected

49, Not connected

50, Direct supply from battery

51, Not connected

52, Not connected

53, Not connected

54, Not connected

55, Not connected

56, Not connected

57, Not connected

58, Not connected

59, Not connected

60, Not connected

61, Fuel temperature sensor signal

62, Not connected

63, Not connected

64, High speed H CAN 1 line

65, Accelerator potentiometer track 1 signal

66, W communication line

67, Not connected

68, Brake pedal switch signal (N.C.)

69, Not connected

70, Plug preheating unit test input

71, Not connected

72, Not connected

73, Not connected

74, Plug preheating relay control

75, Fuel pump relay control

76, Fuel heater relay control

77, Not connected

78, Injection system fault warning light (MIL)

79, Air conditioning compressor control

80, Main relay control

81, Not connected

82, Not connected

83, Accelerator potentiometer track 1 supply

84, Not connected

85, Not connected

86, Not connected

87, Air condioning linear sensor signal

88, Diagnostic line K

89, Not connected

90, Water in diesel filter sensor signal

91, Not connected

92, Normally open brake pedal switch signal

93, Clutch pedal switch

SPECIFCATIONS

This is fitted on the cylinder block/crankcase, 'facing' the phonic wheel on the engine flywheel.

It is of the inductive type, i.e. it functions by means of the variation in the magnetic field generated by the passage of the teeth of the flywheel (60-2 teeth).

The fuel injection control unit uses the rpm sensor to:

• determine the rotation speed;
• determine the angle of the crankshaft.

SPECIFCATIONS

The figure shows the rpm sensor components.

1 - Brass bush

2 - Permanent magnet

3 - Plastic sensor casing

4 - Coil winding

5 - Polar core

6 - Ring gear or flywheel

7 - Coaxial two-wire cable or electrical connection

SPECIFCATIONS

PIN-OUT

TECHNICAL SPECIFICATIONS

Winding resistance 790 Ohm ± 20%

Winding resistance 680 mH ± 20% (f=1kHz)

The distance (gap) for obtaining correct signals, between the end of the sensor and the flywheel, should be between 0.8 and 1.5 mm.

This gap is not adjustable, so if a value outside the tolerance range is measured, check the condition of the sensor and the flywheel.

The graph shows sthe sensor output signal in relation to the horizontal development of the phonic wheel.

1 - Toothed wheel profile

2 - Rpm sensor signal

3 - Reference tooth

4 - TDC recognition point

OPERATION

The passage from full to empty, due to the presence or absence of the tooth, causes a variation in the magnetic flow which is sufficient to generate an induced alternating voltage, resulting from the count of teeth located on a ring (or phonic wheel).

The frequency and range of the voltage sent to the electronic control unit provides it with the angular speed of the crankshaft.

SPECIFCATIONS

Hall effect, fitted on the cylinder head and 'facing' the cams.

This pulley comprises a tooth which enables the timing sensor to indicate the engine's timing position.

The fuel injection control unit uses the timing sensor signal to recognise the TDC at the end of compression, and during starting so as to synchronise the engine management control unit with the engine.

The sensor is fitted near the exhaust camshaft.

OPERATING

A semiconducting layer, through which current passes, immersed in a perpendicular magnetic field (force lines perpendicular to the current direction), generates at its ends a difference in potential known as Hall voltage.

If the intensity of the current remains constant, the voltage generated only depends on the intensity of the magnetic field; the intensity of the field simply has to vary periodically to produce a modulated electrical signal, whose frequency is proportional to the speed with which it changes magnetic field. To obtain this change, a tooth on the inside of the pulley moves close to the sensor.

OPERATING

PIN-OUT

In the specific case of the timing sensor, it is supplied by the engine management control unit at 5 V.

Whenever the rotor passes in front of the sensor, a Hall-effect change in output voltage from the sensor is generated; this change takes place throughout the duration of the passage of the rotor in front of the sensor, after which the signal returns to the initial value (5V).

SPECIFCATIONS

The turbocharging pressure sensor is fitted on the inlet manifold and allows an inlet pressure of up to 1.5 bar to be measured (corresponding to 2.5 bar absolute).

The sensitive element consists of a piezoresistive eleent whose signal is amplified by an electronic circuit integrated in the sensor. The sensor is supplied directly by the electronic control unit with a voltage of 5 V, and as an output supplies a voltage directly proportional to the turbocharging pressure.

SPECIFCATIONS

Excess pressure sensor pin out

SPECIFCATIONS

It is fitted on the thermostatic cup and measures the temperature of the coolant by means of an NTC which has a negative resistance coefficient.

SPECIFCATIONS

Engine coolant temperature sensor specifications

SPECIFCATIONS

The flow meter is located on the air inlet duct and is of the 'hot film' type.

An arrow on the flow meter outer casing indicates the direction of the air flow.

SPECIFCATIONS

Air flow meter pin out

The air flow meter cannot be dismantled.

OPERATION

The operating principle is based on a diaphragm located in a measuring duct through which the intake air entering the engine flows.

The hot film diaphragm is kept at a constant temperature (about 120°C above the incoming air temperature) by the heating resistor.

The air mass passing through the measuring duct tends to draw heat from the diaphragm, so to keep the latter at a constant temperature, some current must flow through the resistor.

The figure shows the general diagram of the flow meter's sensitive element.

OPERATION

The platinum hot-film sensor is a PTC (positive temperature coefficient) thermal resistor, i.e. a resistor whose value increases as the temperature increases.

As the quantity of air taken in increases, the amount of heat drawn from the sensor increases, so there is a reduction in the sensor's resistance. As this is inserted in a 'bridge' measurement circuit, it causes an increase in the output voltage, measured by the ECU to calculate the volume of air drawn in by the engine.

The flow meter is also able to distinguish the direction of the air flow, so the information relates to the actual quantity of air drawn in by the engine, unaffected by any turbulence.

OPERATION

Air flow meter specifications

The air temperature sensor is built into the flow meter. This sensor is of the NTC type: the nominal resistance is 2000 Ohm at a temperature of 25 °C.

OPERATION

The flow meter directly measures the air mass (not volume), thus eliminating problems of temperature, altitude, pressure, etc.

Specifications

It is built into the fuel heater and measures the temperature of the coolant by means of an NTC thermistor which has a negative resistance coefficient.

Specifications

Fuel temperature sensor pin out

Fuel temperature sensor specifications

The sensor is based on semiconductor technology; so if the sensor temperature increases as the fuel temperature increases, the resistance decreases.

As the variation in resistance is not linear, for the same temperature increment, it is higher for low temperatures than for high temperatures.

SPECIFCATIONS

It is fitted at the end of the 'rail' fuel distribution manifold and has the task of supplying the injection control unit with a 'feedback' signal to:

• regulate the injection pressure
• regulating injection duration.

SPECIFCATIONS

The sensor is supplied directly by the engine management control unit with a voltage of 5 V. The output voltage varies linearly between 0.5 V (0 bar) and 4.5 V (1500 bar).

SPECIFCATIONS

Fuel pressure sensor pin out

CONSTRUCTION FEATURES

The sensor consists of a casing, secured to the accelerator pedal mount, which contains a shaft, in an axial position, connected to two potentiometers: one main one and one safety one.

There is a coil spring on the shaft which guarantees the correct resistance to the pressure whilst a second spring ensures the return on release.

The redundant reading of the signal makes it possible to continuously monitor the plausibility of the values measured, so as to ensure completely safe driving, even in the event of a fault.

OPERATION

The position of the accelerator pedal is transformed into an electrical voltage signal and is sent to the fuel injection control unit by the potentiometer connected to the accelerator pedal.

The accelerator pedal position signal is processed together with the information relating to the rpm, to obtain the fuel injection times and relevant pressure.

BOSCH SENSOR TECHNICAL SPECIFICATIONS

Supply voltage: 5V ± 0.3V

Resistance at potentiometer slide terminals:: 1 kOhm ± 0.4 kOhm

Track 1 resistance: 1.2 kOhm ± 0.4 kOhm

Track 2 resistance: 1.7 kOhm ± 0.8 kOhm

HELLA SENSOR TECHNICAL SPECIFICATIONS

Supply voltage: 5V ± 0.3V

Resistance at potentiometer slide terminals:: 1 kOhm ± 0.4 kOhm

Track 1 resistance: 0.9 kOhm ± 35% ....1.4 kOhm ± 35%

Track 2 resistance: 1.2 kOhm ± 35% ....2.0 kOhm ± 35%

CONSTRUCTION FEATURES

The fuel pressure regulator is fitted on the rail and regulates the fuel pressure in accordance with commands from the engine management control unit, via a ball valve which discharges the fuel ont he low-pressure line to the fuel tank.

CONSTRUCTION FEATURES

The fuel pressure regulator contains a solenoid which is controlled by the engine management control unit by the PWM method (carrier 1 kHz). When the duty cycle is set to 0%, the solenoid is not supplied: there is minimum pressure in the rail because of the preload of the ball valve spring.

ELECTRICAL SPECIFICATIONS

Resistance: 2.07 - 2.53 (ohm) at 20 °C

Maximum current 2.5 A

Minimum pressure not supplied 50 bar

CONSTRUCTION FEATURES

The electric fuel pump supplies the high-pressure pump. It is fully immersed in the fuel in the fuel tank. The pump assembly is designed so as to obtain the maximum fuel level in the suction area.

This function is achieved by a Venturi located on the return pipe to the suction area, rather than to the fuel tank. The pumping unit is of the roller type and permits a capacity of 160 litres/hour.

The pump comprises a permanent-magnet electric motor which is continuously supplied when the engine is on. The fuel sent to the high-pressure pump which has not been used flows back into the tank through a pressure-relief valve mounted on the filter unit.

The pump has a further pressure-relief valve, so as to avoid damage to the pumping unit if the delivery pipe becomes blocked.

TECHNICAL SPECIFICATIONS

Absorbed current < = 4.6 A (supply voltage 13 V)

Capacity > = 150 l/h

Working pressure 200 - 400 kPa

CONSTRUCTION FEATURES

The device interfaces with and is controlled by the engine management system in accordance with the EOBD protocol. It has been designed to carry out all the operating and monitoring functions for the operation of the individual heater plugs during the pre-heating stage for diesel engines.

The control unit comprises a protection against high currents and high voltrages, and has a control logic which, in the event of a fault, acts as an auto-reset electronic fuse.

Because of its thermal characteristics and resistance to external agents, the device can be fitted directly in the engine compartment.

The control unit is protected on all terminals against the possible reversed connection of battery terminals, and is built in such a way as to withstand all stresses occurring in the vehicle.

CONSTRUCTION FEATURES

The unit has the following connecting termnals:

CONSTRUCTION FEATURES

The rail consists of a forged steel tube designed to withstand the high operating pressures in the high-pressure system.

CONSTRUCTION FEATURES

The internal volume in the rail is cm3: this volume has been determined so as to minimise pressure peaks due to the injection process, without slowing down the commands to change the fuel pressure set by the engine management control unit, in order to optimise combustion.

The fuel from the high-pressure pump reaches the rail and is then taken to the injectors. A pressure sensor and the high-pressure regulator are mounted on the rail.

CONSTRUCTION FEATURES

The high-pressure pump is of the CP1 Compact type with three radial pistons The capacity is 567 mm3/revolution and the rotation speed, being mounted on the camshaft, is equal to half the speed of rotation of the crankshaft (reduction ratio 2:1). The pump is lubricated and cooled by the flow of fuel passing through it: the necessary flow rate is provided by the low-pressure pump. This supplies the pump with a quantity of fuel which always exceeds the engine's requirement, so as to create a recirculation of fuel towards the tank, and so the pump is lubricated (as a priority) and cooled.

The movement of the pistons is deterined by a cam joined to the pump shaft: this drives a polygonal ring which acts on the piston small end.

Each pumping unit has an inlet plate valve and a delivery supply valve.

The pump comprises a shutoff valve: this protects the pump in the event of a low flow rate from the low-pressure supply, thus ensuring lubrication to the pumping units and cam mechanism.

TECHNICAL SPECIFICATIONS

Radial pump with 3 pumping units

Capacity 567 [mm3/revolution]

Efficiency: > 79% at 1350 bar at 1000 rpm

Nominal pressure: 1350 bar

CONSTRUCTION FEATURES

The diesel heater is built into the diesel filter cover and comprises three resistors which are supplied by the control unit in accordance with the signal from the fuel temperature sensor.

CONSTRUCTION FEATURES

DIESEL FILTER CONNECTOR PIN-OU

CONSTRUCTION FEATURES

Inserted in the diesel filter container casing, at the bottom, it indicates the presence of water via the warning light on the instrument panel.

1 - Water presence sensor

2 - Diesel filter casing

3 - Filter element