FOR 1C2X AND B0F7C AND DVY01 AND SINCE O 8001 OR
FOR 1CN6 AND B0F2X AND DVY01 AND SINCE O 8211 TO O 8688 OR
FOR 1CN7 AND B0F2X AND DVY01 AND SINCE O 8688 OR
FOR 1CX4 AND B0F2X AND DVY01 AND SINCE O 8688 OR
FOR 1CX4 AND B0F7C AND DVY01 AND SINCE O 8688 OR
FOR 1CU6 AND B0F7C AND DVY01 AND SINCE O 8276 OR
FOR 2CM4 AND B0F2X AND DVY01 AND SINCE O 8358 OR
FOR 1C6N AND B0F2X AND DVY01 AND SINCE O 8365 OR
FOR 2CU6 AND B0F7C AND DVY01 AND SINCE O 8421 OR
FOR 2CU6 AND B0F7U AND DVY01 AND SINCE O 8421
The high pressure fuel pump receives "low pressure" fuel from the booster pump.
Role of the high pressure fuel pump (BOSCH CP1 type with 3 pistons) :
The high pressure fuel pump is driven by the timing belt (drive ratio 0,5).
Fig : B1HP118C
A:high pressure fuel outlet (to the common injection rail).
B:return to fuel tank.
C:fuel inlet (booster pump).
(1) fuel high pressure regulator.
(2) lubricating valve.
(3) eccentric pump shaft.
(4) high pressure piston.
(5) deactivator of the 3rd piston of the high pressure fuel pump.
The high pressure fuel varies between 200 and 1350 bar.
Maximum absorbed power:3,5kW.
The lubricating valve lubricates the high pressure fuel pump in case the booster pressure is too low.
Fig : B1HP119D
Difference between the booster pressure and the pressure in the fuel tank return circuit :B:return to fuel tank.
C:fuel inlet (booster pump).
D:to high pressure stage.
(2) lubricating valve.
(6) return spring.
The fuel enters the pump through inlet "c" and passes through the lubrication valve (2) (booster pump).
A :Pressure less than 0,8 bar :Fig : B1HP11AD
C:suction phase.
D:delivery phase.
(3) eccentric pump shaft.
(4) high pressure piston.
(7) fuel suction valve.
(8) delivery ball valve.
(9) suction valve return spring.
(10) high pressure piston return spring.
(11) drive cam.
The shaft of the high pressure fuel pump contains a cam.
The injection pistons are supplied with fuel by the low pressure circuit inside the high pressure pump.
The fuel is drawn in by the piston during the suction phase.
C Suction phase :After top dead centre, the delivery valve closes following the reduction in pressure.
Fig : B1HP11BD
E:using 3 pistons.
F:using 2 pistons.
(4) high pressure piston.
(5) deactivator of the 3rd piston of the high pressure fuel pump.
(7) fuel suction valve.
(8) delivery ball valve.
(9) suction valve return spring.
(12) push rod.
Components of the deactivator of the 3rd piston of the high pressure fuel pump :Control:injection ECU.
Type:"all or nothing" control through earth.
When the 3rd piston deactivator is energised:the pump operates on 2 pistons.
When the 3rd piston deactivator is not energised:the pump operates on 3 pistons.
The high pressure fuel regulator regulates the pressure of the fuel at the outlet of the high pressure fuel pump.
Fig : B1HP11CD
G:high pressure regulator not energised.
H:high pressure regulator energised.
A:high pressure fuel outlet (to the common injection rail).
B:return to fuel tank.
E:high pressure fuel circuit.
(13) spring.
(14) electric coil.
(15) magnetic core.
(16) ball.
The fuel high pressure is regulated by modifying the rating of the high pressure fuel regulator.
The high pressure fuel regulator consists of 2 pressure control circuits :The high pressure fuel circuit is subject to pressure variations.
The fuel high pressure increases when a pump piston delivers.
The fuel high pressure decreases when a diesel injector is opened.
The movement of the ball dampens pressure variations.
When the high pressure fuel regulator is not energised:the pressure is limited to ð 100 bar.
Control:injection ECU (earth).
Variable voltage control (OCR) :
|
The fuel high pressure common injection rail acts as a fuel accumulator.
The fuel is available for all diesel injectors.
The volume of the fuel high pressure common injection rail is suited to the engine capacity.
The charge level of the battery is important for the HDI direct injection system to operate.
The double injection relay is controlled directly by the injection ECU.
The first relay of the double injection relay supplies the following components :The sensor is linked to the accelerator pedal by a cable.
The wheel sensor :Using this information, the ECU works out the fuel flow to inject (time and injection pressure).
Fig : B1HP11DC
(17) electrical connector.
(18) accelerator cable.
(19) drive cam.
The accelerator pedal sensor provides 2 signals (voltage).
The voltage value of one signal is equivalent to half of the other one.
Items of information from the connector channels are constantly compared with each other to detect a possible fault.
In the engine compartment.
The sensor is located opposite the teeth of the flywheel.
The sensor is used to work out the following parameters :Fig : B1HP06VC
The sensor is of the inductive type.
Components of the sensor :The sensor provides an electrical signal every time a tooth on the flywheel passes by (change in magnetic field).
The 58 teeth are used to work out the engine speed.
The 2 missing teeth are used to work out the crankshaft position (no signal).
Resistance between channels 1 and 2:50 ohms.
Features of the signals emitted:variable frequency alternating voltage.
Location:on the clutch housing.
Fig : B1HP11ED
"Hall effect" sensor.
(20) camshaft position sensor.
(21) camshaft pulley.
(22) target driven by the camshaft.
(23) camshaft hub.
(24) plastic lug.
The camshaft sensor provides a square signal for the injection ECU.
The camshaft sensor is located opposite a target driven by the camshaft pulley.
The sensor is used to synchronise fuel injections with respect to piston position (sequential injection).
The plastic lug (24) is used to adjust the air gap in the factory.
|
Air and fuel supply:injection ECU.
Allocation of the connector channels :The voltage slots are between 0 and 5 volts.
Signal emitted :The engine coolant temperature sensor informs the ECU about the engine coolant temperature.
Role of the injection ECU according to the data received :The sensor consists of 2 NTC (negative temperature coefficient resistor).
Allocation of the connector channels :The sensor consists of a Negative Temperature Coefficient (NTC) resistor.
The higher the temperature, the greater its resistance.
Electrical specifications:resistance at 20 °C =6200 ohms.
Fig : B1GP078C
(25) engine coolant temperature sensor.
The water temperature sensor is fitted to the coolant unit.
There are 2 assembly possibilities.
Metal coolant outlet housing :The air temperature sensor informs the ECU about the temperature of the air taken in.
Role of the injection ECU according to the data received :The sensor consists of a Negative Temperature Coefficient (NTC) resistor.
The more the temperature increases, the more its resistance value is reduced.
Electrical specifications:resistance at 25 °C =3300 ohms.
Fig : B1HP11FC
(26) air temperature sensor.
The air temperature probe is incorporated into the air flow meter.
Fig : B1HP11GC
The sensor consists of a Negative Temperature Coefficient (NTC) resistor.
A variation of this assembly measures the fuel temperature directly on the return to tank circuit :Fig : B1HP11HC
(27) fuel temperature sensor.
The fuel temperature sensor is secured to the fuel high pressure common injection rail (28).
The sensor measures the value of the high pressure in the fuel high pressure common injection rail.
Role of the injection ECU according to the data received :Fig : B1HP11JC
(29) fuel high pressure sensor.
(30) metal seal.
The sensor is of the piezoelectrical type.
The sensor consists of stress gauges.
The sensor provides a voltage which is proportional to the fuel pressure in the high pressure common injection rail.
Voltage provided for a pressure of 100 bar:ð 0,5 volt.
Voltage provided for a pressure of 300 bar:ð 1,3 volt.
Fig : B1HP11KC
(29) fuel high pressure sensor.
The sensor is located on the fuel high pressure common injection rail (28).
Fig : B2CP399C
The sensor informs the ECU of the speed of the vehicle.
"Hall effect" sensor :The sensor in located in the gearbox.
The switch ensures the injection ECU provides good driving pleasure.
The brake switch is located on the pedal.
The ECU controls the whole injection system.
The ECU software integrates :The atmospheric pressure sensor can not be separated from the injection ECU.
The ECU contains a power stage which can supply the very high control current required for the diesel injectors to operate.
The injection ECU is connected to the injection harness by a 88-way connector.
The injection ECU software is updated by downloading (ECU fitted with a flash EPROM).
Channel No. | Description |
1 | +12 volts supply (after double relay) |
2 | Output:control of injector N° 1 |
3 | Output:control of injector N° 3 |
4 | Output:control of injector N° 4 |
5 | Output:control of injector N° 2 |
6 | Output:control of injector N° 2 |
7 | --- |
8 | Diagnostic line for the coils of the fan unit control relays |
9 | --- |
10 | Diagnostic line l |
11 | Input:air temperature sensor (flowmeter) |
12 | 5 volt output:sensor supply |
13 | Input:air flow signal (flowmeter) |
14 | Input:engine speed sensor signal |
15 | Input:accelerator pedal sensor signal |
16 | --- |
17 | --- |
18 | Input:camshaft sensor signal |
19 | Input:vehicle speed (vehicle speed sensor) |
20 | --- |
21-22 | --- |
23 | Output:engine coolant temperature information (gauge and warning lamp in the instrument panel) |
24 | --- |
25 | Output:control of fan unit group 1 |
26 | Output:boost pressure regulation electrovalve |
27 | Earth:air conditioning pressostat |
28 | --- |
29 | +12 volts supply (after double relay) |
30 | Output:control of injector N° 1 |
31 | Output:control of injector N° 3 |
32 | Output:control of injector N° 4 |
33 | Earth |
34 | Sensors earth |
35 | --- |
36 | Engine immobiliser serial line |
37 | --- |
38 | Diagnostic line k |
39 | Input:fuel temperature sensor |
40 | Earth |
41 | Input:engine speed sensor signal |
42-43 | --- |
44 | Power supply to sensors (5 volts) |
45 | Earth:water temperature sensor |
46 | Input:engine coolant temperature information |
47 | Input:air conditioning on information (AC/ON) |
48 | Input:stop lamp switch connection |
49 | Earth |
50 | Input:fuel pressure information |
51 | Earth |
52 | Output:recycling electrovalve control (EGR) |
53 | Earth |
54-55 | --- |
56 | Output:preheating warning lamp |
57 | --- |
58 | Output 1:control of additional heating 1 |
59-60 | --- |
61 | --- |
62 | Output:engine speed to instrument panel |
63 | Output:fuel consumption at any moment (trip computer) |
64 | Input:accelerator pedal sensor |
65 | --- |
66 | Input:wake up for injection ECU, wake up for ADC |
67 | Output:control for preheating unit |
68 | Input:accelerator pedal sensor |
69 | After ignition + |
70 | Input:catalytic converter temperature |
71 | Input:inlet manifold air pressure |
72 | --- |
73 | Input:unused brake switch |
74 | Input:fuel pressure |
75 | Air conditioning pressostat (26 bar control stage) |
76-79 | --- |
80 | Output:deactivator of the 3rd piston of the high pressure fuel pump |
81 | Output:engine coolant temperature information (instrument panel) |
82 | Output:diagnostic warning lamp (instrument panel) |
83 | Output:control of fan unit group 2 |
84 | Output:air conditioning compressor control |
85 | Output 2:control of additional heating 2 |
86 | Output:double relay control |
87 | Output:double relay control |
88 | Output:control for preheating unit |
The control stages incorporated into the injection ECU each have a capacitor which stores the power required to control the diesel injectors.
Between each injection, the injection ECU sends pulses on the coil of the injector which is not working.
The pulses create an induced voltage to charge the corresponding control stage (capacitor).
A safety system inside the ECU disconnects the control stages when the engine is switched off.
|
The diesel injectors inject the amount of fuel required for the engine to operate.
Injecting the fuel directly into the top of the pistons improves engine efficiency.
The fuel can be injected in the following cases :Fig : B1HP11LD
F:return to fuel tank.
(30) electrical connector.
(31) control electrovalve coil.
(32) control electrovalve spring.
(33) nut.
(34) control electrovalve needle.
(35) diesel injector tip.
(36) diesel injector needle.
(37) pressure chamber.
(38) diesel injector spring.
(39) control piston.
(40) control chamber.
(41) supply nozzle.
(42) fuel return circuit nozzle.
(43) high pressure fuel inlet connector.
(44) laminar filter included in the connector (43).
The control electrovalve is located in the upper part of the diesel injector.
The control electrovalve is secured to the body of the diesel injector by the nut (33).
The diesel injectors have 5 holes which encourage air/fuel mixing.
|
The fuel pressures used in the HDI direct injection system prevent the diesel injectors from being directly electrically controlled.
The diesel injectors open due to the pressure difference between the control chamber (40) and the pressure chamber (37).
The diesel injector needle (36) is held against its seat by the spring (38).
The control piston (36) is fitted on top of the diesel injector needle (39) (the control piston is free within its bore).
The top of the control piston opens out into the control chamber (40).
The control chamber is connected to the following circuits :The control chamber (40) is isolated from the fuel return circuit by the electrovalve needle (34).
The diesel injector needle (36) is held against its seat by the spring (32).
The fuel is distributed evenly between chambers (40) and (37).
Nozzle (42) is larger than nozzle (41).
The electrovalve needle rises as soon as the electrovalve coil is energised (magnetic field).
Fig : B1HP11MD
J:diesel injector closed.
K:opening of a diesel injector.
(34) control electrovalve needle.
(36) diesel injector needle.
(37) pressure chamber.
(38) diesel injector spring.
(39) control piston.
(40) control chamber.
(41) supply nozzle.
(42) fuel return circuit nozzle.
The force exerted by the high pressure is the same between the control chamber (40) and the pressure chamber (37).
The control piston is locked (held against the diesel injector needle).
The rise in pressure in the fuel high pressure common injection rail encourages the diesel injector to close.
The injection ECU supplies the control electrovalve.
Operating phase as soon as the electrovalve needle (34) lifts up under the action of the control electrovalve (magnetic field) :Fig : D3AP015C
Diesel injector control current.
Y:amps.
X:duration.
(45) initial current.
(46) holding current.
(47) initial phase.
(48) holding phase.
(49) end of control.
The electrical supply to an electrovalve consists of 2 phases :The aim of the initial phase is to cause the electrovalve needle to rise rapidly.
The diesel injector electrovalve is supplied as follows :The holding phase is used to continue the supply to the electrovalve whilst limiting the electrical power absorbed.
The diesel injector electrovalve is supplied as follows :