Curriculum Training

Curriculum Training

Diesel Injection and Engine ManagementSystems

VP30/VP44 Distributor Fuel Injection Pump Systems

Technical Service TrainingCG 8182/S en 12/2005

TC3043050H

To the best of our knowledge, the illustrations, technical information, data and descriptions in this issue were correct at the timeof going to print. The right to change prices, specifications, equipment and maintenance instructions at any time without noticeis reserved as part of FORD policy of continuous development and improvement for the benefit of our customers.

No part of this publication may be reproduced, stored in a data processing system or transmitted in any form, electronic,mechanical, photocopy, recording, translation or by any other means without prior permission of Ford-Werke GmbH. No liabilitycan be accepted for any inaccuracies in this publication, although every possible care has been taken to make it as complete andaccurate as possible.

Copyright 2005

Ford-Werke GmbHService training programs D-F/GT1 (GB)

More stringent exhaust and noise emission standards and requirements regarding low fuel consumption continueto place new demands on the fuel injection system of diesel engines. To ensure these requirements are met, theinjection system has to inject the fuel into the combustion chamber at high pressure to achieve good mixturepreparation and, in the process, must also meter the injected fuel quantity as accurately as possible.Since the introduction of the 1.8L Endura-DI (Kent) diesel engine in the 1999 Ford Focus, the then still partiallymechanical control of the diesel fuel injection systems has progressively been superseded by systems withfully-electronic control.

The VP30/VP44 distributor fuel injection pump systems are characterized by high precision in terms of injectedfuel quantity and start of injection timing and by high injection pressure.The fuel quantity is controlled fully electronically and time-controlled by a high-pressure solenoid valve, which isactuated by a pump control unit.

Completion of the E-learning program "Diesel Fuel Injection and Engine Management Systems" is a prerequisitefor the study of this Student Information.

This Student Information is divided into lessons. It has been designed as a self-learning tool in accordance with thenew Ford training concept.

The beginning of each lesson lists the goals that are to be achieved by working through the lesson. At the end ofeach lesson there is a set of test questions which are designed to monitor the student's progress. The solutions tothese test questions can be found at the end of the Student Information.

Please remember that our training literature has been prepared for FORD TRAINING PURPOSES only. Repairsand adjustments MUST always be carried out according to the instructions and specifications in the workshopliterature. Please make full use of the training offered by Ford Technical Training Courses to gain extensiveknowledge of both theory and practice.

1Service Training (G544935)

Preface

Preface..............................................................................................................................

Lesson 1 General Information

5Objectives....................................................................................................................................................

6Overview of fuel injection systems.................................................................................................................................

7Injection characteristics...................................................................................................................................................

10Test questions..............................................................................................................................................

Lesson 2 Distributor Type Fuel Injection Systems

11Objectives....................................................................................................................................................

12Overview.........................................................................................................................................................................

13Characteristics.................................................................................................................................................................

13Special features...............................................................................................................................................................

14PCM................................................................................................................................................................................

17Glow plug control system...............................................................................................................................................

19Sensors.........................................................................................................................................................

19MAF sensor.....................................................................................................................................................................

19MAP................................................................................................................................................................................

20IAT sensor.......................................................................................................................................................................

21MAPT sensor..................................................................................................................................................................

21CHT sensor.....................................................................................................................................................................

23APP sensor......................................................................................................................................................................

24CKP sensor......................................................................................................................................................................

25VSS signal.......................................................................................................................................................................

25BARO sensor...................................................................................................................................................................

Service Training2

Table of Contents

26Position sensor in EGR valve..........................................................................................................................................

27Stoplamp and BPP switches............................................................................................................................................

27CPP..................................................................................................................................................................................

28EGR solenoid valve and wastegate control solenoid valve.............................................................................................

29Actuators.....................................................................................................................................................

29Pump control unit............................................................................................................................................................

30High-pressure solenoid valve..........................................................................................................................................

30Timing device solenoid valve..........................................................................................................................................

31Rotational angle sensor...................................................................................................................................................

34Strategies.....................................................................................................................................................

34Fuel metering calculations..............................................................................................................................................

35Control of the fuel limitation quantity............................................................................................................................

35Judder damper.................................................................................................................................................................

36Idle speed control............................................................................................................................................................

36Smooth-running control (cylinder balancing).................................................................................................................

37Switching off the engine.................................................................................................................................................

37Fuel delivery....................................................................................................................................................................

39Synchronization of the fuel injection pump....................................................................................................................

41EGR system.....................................................................................................................................................................

42Boost pressure control.....................................................................................................................................................

45Data exchange.................................................................................................................................................................

45PCM fault strategy..........................................................................................................................................................

46EOBD..............................................................................................................................................................................

49Fuel system..................................................................................................................................................

49Overview of the fuel system...........................................................................................................................................

50Fuel injectors...................................................................................................................................................................

3Service Training

Table of Contents

52Injection lines..................................................................................................................................................................

53VP30.............................................................................................................................................................

53Overview.........................................................................................................................................................................

55Fuel supply metering by the high-pressure solenoid valve.............................................................................................

57VP44.............................................................................................................................................................

57Overview.........................................................................................................................................................................

59Components of the Bosch radial piston distributor fuel injection pump VP44..............................................................

61Fuel metering via the high-pressure solenoid valve........................................................................................................

63Start of injection adjustment function.............................................................................................................................

65Test questions..............................................................................................................................................

67Answers to the test questions.........................................................................................

68List of Abbreviations.......................................................................................................

Service Training4

Table of Contents

On completing this lesson, you will be able to: explain why the VP30/VP44 distributor fuel injection pump systems are used. state the reasons for the use of pre-injection. explain what effect pre-injection has on combustion.


ObjectivesLesson 1 General Information

Overview of fuel injection systems

E65488

Bosch VP 30 distributor fuel injection pumpABosch VP 44 distributor fuel injection pumpB

PCM (Powertrain Control Module)1

Increasingly higher demands are being placed on moderndiesel engines. The focus is not alone on exhaustemissions but also on increasing environmentalawareness and the demand for increasingly bettereconomy and enhanced driving comfort.

This requires the use of complex injection systems, highinjection pressures and precise fuel metering by fullyelectronically-controlled systems.

The high injection pressures convert the fuel, via theinjector nozzle, into tiny droplets, which, again thanksto the high pressure, can then be optimally distributedin the combustion chamber. This results in fewerunburned HC (Hydrocarbon)s, less CO (CarbonMonoxide) and less diesel exhaust particulates beingproduced in the subsequent combustion stage.

(G544936) Service Training6


In addition, the optimized mixture formation reducesfuel consumption.

The above-mentioned demands on current diesel engineslikewise lead to high demands on the diesel fuelinjection and engine management system, e. g.: high injection pressures, shaping of injection timing characteristics, pre-injection, injected fuel quantity, start of injection and boost

pressure values adapted to every operating condition,

load-independent idle speed control,

controlled EGR (Exhaust Gas Recirculation), low injection timing and injected quantity tolerances

and high degree of precision for the entire servicelife,

options to interact with other systems, such asstability assist, PATS (Passive Anti-Theft System),

comprehensive diagnostic facilities,

substitute strategies in the event of faults.

The VP30/VP44 distributor fuel injection pumpsystems have a large range of features to meet thesedemands.

The VP30 is a high-pressure solenoid valve controlleddistributor fuel injection pump which operates accordingto the axial piston principle. It is based on the VP 20and VP 37 distributor fuel injection pump.The VP44 is also a high-pressure solenoid valvecontrolled distributor fuel injection pump. However, itoperates according to the radial piston principle as foundin Lucas fuel injection systems (types DPC and DPCN).

With fully electronic fuel injection and enginemanagement systems, the driver has no direct influenceon the injected fuel quantity as the accelerator pedal hasno mechanical connection to the pump unit, for example.Here, the injected fuel quantity is determined by a rangeof variables. These include:

driver demand (accelerator pedal position), operating state,

engine temperature,

effects on exhaust emissions,

protection against engine and transmission damage,

faults in the system.

Using these parameters, the injected fuel quantity iscalculated in the PCM and fuel injection timing can bevaried.

Fuel metering is performed fully electronically by ahigh-pressure solenoid valve which is located in thedistributor fuel injection pump and controlled by thepump control unit.

The fully-electronic diesel engine management systemfeatures a comprehensive fail-safe concept (integratedin the PCM software). It detects any deviations andmalfunctions and initiates corresponding actionsdepending on the resulting effects (e.g. limiting thepower output by reducing the quantity of fuel).

Injection characteristicsAs already mentioned at the beginning of the lesson,the exhaust emissions and fuel consumption of anengine are of great significance. These factors can onlybe minimized through precise operation of the injectionsystem and comprehensive engine managementstrategies.



Consequently, the following requirements are made ofthe VP30/VP44 distributor fuel injection pump system: The injection timing must be exact. Even small

variations have a significant effect on fuelconsumption, exhaust emissions and combustionnoise,

Injection must be terminated reliably. Calculationof the injected quantity and the injection timing areprecisely adapted to the mechanical components ofthe injection system. Uncontrolled fuel dribble(caused for example by a defective fuel injectornozzle) results in increased exhaust emissions andincreased fuel consumption.

Simple main injection:

Needle lift of fuel injector nozzle and pressure curve inthe cylinder without pre-injection

E64973

1

2

3

4

5

Combustion pressure in the cylinder1

Needle lift2

TDC (Top Dead Center)3Needle lift for main injection4Crank angle5

In most VP30/VP44 distributor fuel injection pumpsystems (except the 2001 Mondeo), the fuel injectionon the pump side is via simple main injection.In the pressure curve, the combustion pressure increasesonly slightly in the phase BTDC (Before Top DeadCenter), corresponding to compression, but increasesvery sharply at the start of combustion.

The steep pressure rise intensifies the combustion noise.

Pre-injection

Needle lift of fuel injector nozzle and pressure curve inthe cylinder with pre-injection

E64974

1

2

3

4 5

6

Combustion pressure in the cylinder1

Needle lift2

TDC3

Needle lift for pre-injection4Needle lift for main injection5Crank angle6

The 2001 Mondeo also features electronically controlledpre-injection, which is implemented using thehigh-pressure solenoid valve in the distributor fuelinjection pump.



In the case of pre-injection, a small amount of fuel isinjected into the cylinder prior to the main injection.Pre-injection results in a gradual increase in thecombustion pressure, leading to an improvement incombustion quality.

The small, pre-injected fuel quantity is ignited and heatsup the upper part of the cylinder, thereby bringing itinto an optimum temperature range (pre-conditioningof the combustion chamber).This means that the main injection mixture will ignitemore quickly and the rise in temperature will be lessabrupt as a result.

The less abrupt temperature increase also results in aless abrupt increase in combustion pressure, significantlyreducing combustion noise.

Advantage:

Continuous build-up of combustion pressure,resulting in reduced combustion noise,

Reduction of nitrogen oxides in the exhaust gas.



Tick the correct answer or fill in the gaps.

1. Which of the following statements is true?

a. The VP30 is controlled fully electronically and works according to the radial piston principle.

b. The VP30 is controlled purely mechanically and works according to the axial piston principle.

c. The VP44 is controlled fully electronically and operates according to the radial piston principle.

d. The VP44 is controlled fully electronically and operates according to the axial piston principle.

2. What does pre-injection mean?a. Fuel is injected into the combustion chamber during the intake stroke.b. Injection occurs at the start of the compression stroke.c. A small amount of additive is injected into the cylinder prior to the main injection in order to increase the

combustion pressure.

d. A small amount of fuel is injected into the cylinder prior to the main injection.

3. What is the advantage of pre-injection?a. A continuous build-up of the combustion pressure

b. An abrupt increase in combustion pressure, leading to an improvement in combustion quality

c. Significantly higher torque at wide-open throttle

d. The main injected fuel quantity is reduced by more than 50%, significantly lowering fuel consumption.


Lesson 1 General InformationTest questions

On completing this lesson, you will be able to: name the components of the engine management system.

describe how the PCM works and be familiar with the integrated diagnostics.

explain the purpose and function of the individual engine management system components and identify theeffects of component faults as well as their diagnostic function.

specify and explain the basic strategies in the engine management system.

explain the purpose of the EOBD system and be familiar with its function.

name the components of the fuel system.

name the components of the fuel and injection system and be able to explain their function. put the knowledge acquired into practice in diagnostic operations and thus draw conclusions regarding possible

malfunctions of individual components.


ObjectivesLesson 2 Distributor Type Fuel InjectionSystems

Overview

1

2

3

4

5

6

7

8

9

10

11

12

2119

18

17

20

22

23

24

25

26

27

28

29

30

31

32

16

13

14

15

E65499


Lesson 2 Distributor Type Fuel InjectionSystems

CKP (Crankshaft Position) sensor1CHT (Cylinder Head Temperature) sensor2MAP (Manifold Absolute Pressure) sensor3IAT (Intake Air Temperature) sensor4MAPT (Manifold Absolute Pressure andTemperature) sensor

5

MAF (Mass Air Flow) sensor6BARO (Barometric pressure) sensor7EGR valve8

APP (Accelerator Pedal Position) sensor9BPP (Brake Pedal Position) switch10CPP (Clutch Pedal Position) switch11VSS (Vehicle Speed Sensor) signal.12Ignition lock13

Pump control unit (communication with CAN(Controller Area Network) via PCM)

14

Instrument cluster15

PATS transceiver16

PCM17

"Smart Charge" generator control18

DLC (Data Link Connector)19ABS (Anti-Lock Brake System) (communicationwith PCM via CAN)

20

Stability assist control unit (communicationwith PCM via CAN)

21

Intake manifold flap solenoid valve22

EGR solenoid valve23

Wastegate control solenoid valve24

Glow plug warning indicator (also fault indicatorfor vehicles without EOBD (European On-boardDiagnostic))

25

Glow plugs26

Cooling fan motors27

Electric auxiliary heater28

A/C relay29

Air conditioning clutch30

Auxiliary fuel pump (VP44 only)31MIL (Malfunction Indicator Lamp) (display ofemissions-related faults in vehicles with EOBD)

32

Characteristics

The VP30/VP44 fuel injection system has two controlmodules for fully electronic diesel engine management:

a PCM,

a pump control unit.

While the PCM calculates the injected fuel quantity andthe fuel injection timing using the recorded engineenvironment data (cylinder head temperature, boostpressure, etc.), the pump control unit monitors theinternal pump functions (high-pressure solenoid valve,rotational angle sensor and adjustment of injectiontiming).

Special features

Compared with mechanical control, the fully electroniccontrol of the VP30/VP44 distributor fuel injectionpumps takes additional requirements into account.

By providing electronic measurement, flexible electronicdata processing and control circuits with electricalactuators (such as the high-pressure solenoid valve andthe timing device solenoid valve), it supports theprocessing of parameters which cannot be taken intoaccount in the case of mechanical control.



PCM

E47821

A fifth-generation PCM with a 104-pin connector isused.

The PCM is equipped with an Intel 196 microprocessor,which ensures high-speed data processing.

The PCM is the main component of the enginemanagement system. It receives the electrical signalsfrom the sensors and set-point transmitters, evaluatesthese and uses them as a basis for calculating the signalsfor the actuators (for example the wastegate controlsolenoid valve, EGR solenoid valve, etc.).The control program (the software) is stored in amemory. The execution of the program is carried outby a microprocessor.

In addition to the actuators, there are also sensors whichform the interface between the vehicle and the PCM asa processing unit.

The sensors, actuators and the power supply areconnected to the PCM via a multi-pin connector.

Input signals from the sensors can have different forms.

Analog input signals

Analog input signals can have any voltage value withina given range. Examples of analog input signals include:

IAT,

MAP,

ECT (Engine Coolant Temperature).

As the microprocessor of the PCM can only processdigital signals, the analog input signals must first beconverted. This is done internally in the PCM in ananalog-to-digital converter (A/D converter).Inductive input signals

Inductive input signals are pulsed signals that transmitinformation about the engine speed and reference mark.Example

CKP sensor.

The inductive signal is processed in an internal PCMcircuit. Interference pulses are suppressed and the pulsedsignals are converted into digital square-wave signals.

Digital input signals

Digital input signals have only two states:

ON or OFF.

Examples of digital input signals include:

switch signals (BPP or CPP), speed sensor pulses of a Hall sensor (VSS).These signals can be processed directly by themicroprocessor.

E51118

1

2

b

b

a

a

PWM signalFixed frequencya

Variable switch-on timeb



Signal voltage1

Time2

The microprocessor transmits output signals to theactuatorsvia specific output stages. The output signalsfor the actuators can also have different forms:

Switch signals (switch actuators on and off, such asthe A/C clutch.

PWM (Pulse Width Modulation) signals. PWMsignals are square-wave signals with a constantfrequency, but a variable activation time. Using thesesignals, e.g. electro-pneumatic transducers can beactuated at any location (for example the wastegatecontrol solenoid valve or EGR solenoid valve).

The high-performance components for direct actuationof the actuators are integrated in the PCM in such amanner that very good heat dissipation to the housingis ensured.

Integrated diagnosis

In the case of sensor monitoring, the integrateddiagnostics are used to check if there is sufficient supplyto the sensors and whether their signal is in thepermissible range.

Furthermore, it is possible to check whether a sensorsignal is within the permissible range via the controlprogram in the PCM.

In the case of systems which work by means ofclosed-loop control (the EGR system, for example),deviations from a specific control range are alsodiagnosed.

A signal path is deemed to be defective if a fault ispresent beyond a predefined period. The fault is thenstored in the fault memory of the PCM together withfreeze frame data (for example ECT, engine speed, etc.).Back in working order recognition is implementedfor many of the faults. This entails the signal path beingdetected as intact over a defined period of time.

Fault handling: If there are deviations from apermissible set value for a sensor, the PCM switches toa default value. This process is used, for example, forthe following input signals:

ECT, IAT,

MAP, BARO,

MAF.

For some driving functions with higher priority (forexample APP sensor), there are substitute functionswhich, for example, allow the vehicle to continue to bedriven to the next Authorized Ford Dealer.

EOBD

As of 1 January 2004, all newly registered dieselvehicles are required by law to be equipped with EOBD.

EOBD is a component of the PCM software and is usedfor the monitoring of components and systemssignificant to emissions.

Further information on EOBD can be found in Section"Strategies".

Diagnostics

The PCM performs self-monitoring to ensure correctoperation. Malfunctions in the hardware or software ofthe PCM are displayed by means of a DTC (DiagnosticTrouble Code). Additional monitoring (see below) isalso performed.

Reference voltage monitoring:

In the case of reference voltage monitoring, so-calledcomparators compare the individual referencevoltages for the relevant sensors programmed in thePCM to check if they are within limits.

If a set reference voltage of 5 V falls below 4.7 V, afault is stored and the engine is stopped.



EEPROM (Electrically Erasable ProgrammableRead Only Memory) monitoring: The engine adjustment data and freeze frame data is

stored in the EEPROM.

The freeze frame data forms part of the EOBD.Incorrect entries are detected appropriately andindicated by a DTC.

Vehicles with EOBD

Reference voltage monitoring:

Since the engine is stopped in the event of a fault,this is non MIL active monitoring.

EEPROM (Electrically Erasable ProgrammableRead Only Memory) monitoring: Faults are MIL active, as the freeze frame data forms

part of the EOBD.

PCM identification

E65500

--0-

1 2 3

4

Plug-in connection1

PCM family number2

Stub3

Part number4

PCM PCB design

E65501

1

2

3 4

6

75

SCP (Standard Corporate Protocol)1Intel 196 microprocessor with integrated RAM(Random Access Memory)

2

Calculation unit for PATS3

EEPROM (Electrically Erasable ProgrammableRead Only Memory) contains vehicleidentification, PATS and engine adjustment data

4

Power driver5

FEPROM (Flash Erasable Programmable ReadOnly Memory) contains the engine strategyand engine calibration

6

CAN7



PATS

E47823

The PATS intervenes in the engine management system.As a result, the engine cannot be started by unauthorizedpersons.

The starter motor is interrupted and the injected fuelquantity is reduced to "zero". The glow plug warningindicator flashes at a frequency of 4 Hz.

The hardware of the PATS system is installed on thePCB of the PCM (combined PATS).

Glow plug control system

E47824

1

2

34

5

6

7

7

7

7

6

CHT signal1

CKP signal (speed)2PCM3

Glow plug indicator4

Glow plug relay (in central junction box)5Parallel connected fuses (50 A each)6Glow plugs7

NOTE: The glow plug warning indicator has a secondfunction, i.e. if it flashes during driving then it isoperating as a fault indicator, informing the driver thereis a fault in the engine management system.

A glow plug control system is incorporated into thePCM. It performs two functions:

Preheating

The PCM receives the relevant temperature signal fromthe CHT sensor.



The length of the preheating period depends on thetemperature signal (low temperature = longer preheatingperiod).The driver is informed that preheating is in operationby the glow plug indicator in the instrument clustercoming on.

Postheating

Preheating is followed, after engine start, by thepostheating phase.

Postheating helps to reduce engine noise, improve idlingquality and reduce HC emissions through more efficientcombustion just after start-up.The postheating phase is carried out up to an enginespeed or around 2500 rpm.

When 2500 rpm is exceeded, the postheating phase isterminated. The service life of the glow plugs isincreased as a result.

Effects of a fault

Longer start-up at low ambient temperatures

Loud combustion noise after engine starting

Rough running engine



MAF sensor

E47843

Location

In the intake tract, downstream of the air cleaner.

Note: The MAF sensor is only used in conjunction witha variable-geometry turbocharger.

Task / function

The MAF sensor is used primarily to regulate EGR(closed loop control) and less for fuel metering as is thecase on petrol engines.

Effects of faults

In the event of a signal failure, the EGR rate is regulatedusing an emergency-running map.

However, this means that the EGR rate is not regulatedas closely to the operating limit, and as a result thereduction of NOX (Oxides of Nitrogen) emissions isnot regulated as effectively.

Diagnostics

The monitoring system checks:

the sensor for short circuit to ground/battery andopen control circuit.

the sensor for illogical voltage jumps (illogicalvoltage jumps could indicate a loose connection, forexample).

whether the output signal of the MAF sensorcorresponds to the map data. Correct functioning ofthe EGR system is checked in this manner.

MAP

E65502

Location

In the air intake tract, downstream of the turbocharger

Task / function

The boost pressure in the intake manifold is measuredby means of the MAP sensor. The higher the boostpressure, then the greater the maximum quantity of fuelthat can be injected as a function of accelerator positionor engine load.

In systems with a fixed-geometry turbocharger (i.e. noMAF sensor installed), the MAP sensor signal alsoinfluences the EGR system.


SensorsLesson 2 Distributor Type Fuel InjectionSystems

Effects of faults

In the event of a fault, the injected fuel quantity isreduced.

In versions with a variable-geometry turbocharger, theguide vanes of the turbocharger are also openedcompletely.

Diagnostics




whether the output signal of the MAP sensorcorresponds to the map data.

Vehicles with EOBD

A faulty MAP signal leads to restricted operation of theboost pressure control as well as of the EGR system andconsequently to increased exhaust emissions. Thereforethis is an MIL active component.

IAT sensor

E65503

Location

In the air intake tract, downstream of the turbocharger

Task / function

The signal serves as a correction factor to take intoaccount the effect of temperature on the density of thecharge air.

The IAT signal influences the following functions:

Injected fuel quantity Fuel injection timing EGR system

Effects of faults

In the event of a signal failure, the PCM performs thecalculations using a predetermined substitute value. Thiscan lead to loss of power.

Diagnostics




Vehicles with EOBD

A faulty IAT signal leads to restricted operation of theEGR system as well as to inaccurate fuel metering.Therefore this is a MIL active component.



Sensors

MAPT sensor

E47839

With the MAPT sensor, the IAT and MAP sensors havebeen combined in a single component. The MAPTsensor therefore performs the same functions as the IATand MAP sensors.

Use of the MAPT or IAT and MAP sensor isversion-specific and has no technical reasons.

CHT sensor

Location

Screwed into the cylinder head

Task / function

Example of installation position of the CHT sensor on the2.4L Duratorq-DI

E47840

1

2

1

3

Cylinder head1

Sensor tip2

CHT sensor3

The CHT sensor (CHT = Cylinder Head Temperature)replaces the ECT - sensor and the temperature sensorfor the temperature display in the instrument cluster.

The CHT sensor is screwed into the cylinder head andmeasures the temperature of the material rather than thecoolant.

As a result, when the engine overheats (e.g. due to lossof coolant) a more precise temperature measurement ispossible.

Note: Once removed, the CHT sensor must always bereplaced with a new one, and the specified tighteningtorque must be observed exactly. Otherwise damage tothe sensor (e.g..through deformation of the sensor tip)cannot be ruled out.



E47841

J

J

1

23

58

4

6

7

PCM1

Second resistor ("pull-up")2First resistor3

CHT sensor (NTC)4Sensor output signal5

Analog/digital converter6

Microprocessor7

For comparison: ECT sensor8

The voltage signal is digitized in the analog/digitalconverter and transmitted in the form of counts to themicroprocessor, which assigns these to thecorresponding temperature values.

At high temperatures, the resolution of the CHT sensoris not enough to sufficiently cover the entire temperaturerange from 40C to +214C. Therefore thetemperature curve is shifted by switching on a secondresistor in the PCM.

E47842-- --

(129)

A B

C

12

32

CountsA

Voltage (V)BMaterial (sensor) temperatureCFirst curve1

Switch point of "pull-up" resistor2

Second curve3

The first curve ranges from a material temperature of-40C to approx. +78C. A transistor in the PCM thenswitches on a second, so-called "pull-up" resistor toextend the sensor signal function. The second curveranges from a material temperature of approx. 62C to214C.

Example: A sensor output voltage of 2.5V(=500counts) can indicate a material temperature of35C as well as one of 129C (see diagram), dependingon which curve the voltage value is assigned to. Whena pull-up resistor is switched on, the microprocessorassigns the second curve the value of "500counts". Thismeans that the material temperature is in the highertemperature range (in this case 129C).Use of CHT signal: Injected fuel quantity Start of injection Idle speed



Sensors

Glow plug control

EGR system

Actuation of the temperature gauge and glow-plugindicator lamp

Effects of faults

Open control circuit: In an open control loop, the system assumes a

maximum temperature value of 120C.

In this case, the cooling fan(s) run(s) continuously.The EGR system and the air conditioning areswitched off. The booster heater is switched off andthe engine runs with reduced power.

Short circuit: In a short circuit, the system assumes a temperature

of > 132 C.

In this situation, the engine will cut out or cannot bestarted.

If the sensor malfunctions or the engine overheats, theengine overheating safety function is activated.

In this mode, engine power is reduced by injecting lessfuel. If the engine temperature increases further, thenthe engine power is reduced further (depending on thevehicle version).Note: To avoid engine damage, it is not possible to startthe engine at a cylinder head temperature below-35C. The reason for this is the large quantities of fuelinjected, which in this case might result in componentsbeing destroyed. Vehicles for cold climates have specialstrategies or engine preheating equipment.

Diagnostics




the signal for a plausible temperature increase.

Vehicles with EOBD

A faulty CHT signal has serious effects on the exhaustgas emissions. Therefore this is a MIL activecomponent.

APP sensor

E47845

Location

Integrated into the accelerator pedal

Task / function

The PCM needs the accelerator pedal position in orderto control engine power according to driver input.



The APP sensor houses a total of three sliding contactpotentiometers.

Effects of faults

Failure of a potentiometer has no influence on engineoperation. Only one DTC is (as a rule) stored in the faultmemory.

If two or three potentiometers fail, continued driving isonly possible at engine idle speed.

Diagnostics



the values of the individual potentiometers forplausibility.

CKP sensor

E65504

Representation of the CKP signalCKP signal (similar to sinusoidal voltage curve)ACKP sensor1

Voltage (V)2

17 pulses per 1/2 crankshaft rotation (180)3Tooth center4

10 tooth spacing5

Extended teeth (reference mark)6Center of gap between teeth7

Circumference of flywheel with 2 x 17 teeth8

Location

On the cylinder block, close to the flywheel

Task / function

The CKP sensor is an inductive pulse generator. It scansa uniform tooth structure on the circumference of theflywheel.

There are a total of 2 x 17 teeth on the circumferenceof the flywheel, whereby two extended teeth indicatethe top and bottom dead center are thus situated 180apart.

The teeth are distributed on the flywheel as follows:

2 x 16 x 10 + 2 x 1 x 20 = 360

A

1 B

2E65505

Higher engine speedA

Lower engine speedB

Zero passages: Spacing small/amplitude large1

Zero passages: Spacing large/amplitude small2



Sensors

Furthermore, the acceleration of the flywheel with eachpower cycle results in a change in the CKP signal.

During the power cycle, the combustion pressure on thepiston causes acceleration of the crankshaft and,consequently, of the flywheel. This can be identified inthe voltage curve by means of the higher frequenciesand amplitudes of the CKP signal.

Effects of faults

In the event of a signal failure, the engine is stopped,or the engine no longer starts.

Diagnostics

If a specified maximum time is exceeded after the lastCKP signal, there is a fault (plausibility check). Thischeck is capable of analyzing driving errors (enginestalling or cutting out).Vehicles with EOBD

As the engine cuts out or cannot be started in the caseof a fault, the sensor has no effect on exhaust gasemissions. Therefore, this is a non MIL activecomponent.

VSS signal.

E47844

Note: In newer versions with ABS, the wheel speedsignals are transmitted to the PCM via CAN, from whichthe PCM generates the vehicle speed.

Location

On the transmission

Task / function

The VSS signal is used:

to calculate the engaged gear,

to reduce engine judder during gear shifting, as information for the trip computer,

as information on vehicle speed for the instrumentcluster,

as information for the speed control systemincorporated into the PCM.

Effects of faults

Engine judder during gear shifting

Diagnostics

The input signals of the sensor are continuously checkedto ensure that they are functioning correctly.

BARO sensor

E65506

1

23

BARO sensor in the 2001 MondeoA-pillar reinforcement1

BARO sensor2

Retaining clip3



Location

Behind the instrument panel on the left on the A-pillarreinforcement

Task / function

The BARO sensor signal is used for value-basedcorrection of the setpoint values for the boost pressurecontrol and EGR control circuits.

The different ambient air densities are taken into accountin this case.

For systems with pre-injection only: The BAROsensor also influences the pre-injected fuel quantity.The BARO sensor is only used in conjunction with avariable-geometry turbocharger.

Effects of faults

Possible increased black smoke formation at higheraltitudes.

Diagnostics



Position sensor in EGR valve

E47849

Location

In the EGR valve

Task / function

Depending on the engine version (as a rule if there isno MAF sensor installed) a position sensor is integratedin the EGR valve, which records the current position ofthe valve and reports it back to the PCM.

The PCM calculates the current EGR quantity based onthis signal.

Each time the ignition is switched on, the PCM performsinitialization of the end positions of the position sensor.Consequently, a misaligned closing / opening point ofthe EGR valve due to coking is taken into account andadjusted.

Effects of faults

The EGR system is switched off.



Sensors

Diagnostics



logical rise/fall times of the signal. The slide tracksare thereby checked for faults (e.g. due to dirt). Thistype of malfunction can also indicate a looseconnection (e.g. on the wiring harness connector).

for plausibility: A seized or sticking EGR valve isdetected in this manner.

Vehicles with EOBD

Since a malfunction leads to the switching off of theEGR system, this is a MIL active component.

Stoplamp and BPP switches

E47850

1 2

Brake pedal switch1

Stoplamp switch2

Location

At the pedals

Task / function

The signal from the stoplamp switch affects fuelmetering when the brake is actuated and when a gear isengaged when idling.

Example: In a braking operation, the PCM receives asignal from the stoplight switch as a result of which thequantity of fuel for idle control is reduced. This preventsthe idle control from continuing to maintain the idlespeed, thus counteracting the braking action.

On vehicles equipped with speed control, there is anadditional brake pedal switch on the pedal mounting.Its only function is to switch off the speed control whenthe brake is actuated.

CPP

E47851

Location

At the pedals

Task / function

The PCM uses the signal from the CPP switch todetermine whether the clutch is being engaged ordisengaged.

The quantity of injected fuel is briefly reduced duringactuation of the clutch to avoid engine judder duringgearshifts.

The CPP switch is located on the pedal mountingbracket.

On vehicles with speed control, the CPP switch switchesoff the speed control when the clutch is disengaged.



Effects of faults

When changing gears, engine judder will occur.

EGR solenoid valve and wastegatecontrol solenoid valve

E47856

1 2

EGR solenoid valve1


Location

In the engine compartment (depending on vehicle andversion)

Task / function

The solenoid valves are supplied with a vacuum by thevacuum pump.

The signals from the PCM control this vacuum, as aresult of which the boost pressure is regulated by meansof a vacuum unit and the EGR flow is regulated by theEGR valve.

The duty cycle of the PWM signals determines thevacuum which is applied at the EGR valve or to theturbocharger vacuum unit.

Effects of faults

Wastegate control solenoid valve

In the event of failure of the solenoid valve, the boostpressure can no longer be regulated. Engine performanceis then reduced.

EGR solenoid valve

In the event of failure of the solenoid valve, the EGRvalve remains closed as the control vacuum is no longerapplied at the EGR valve.

Diagnostics

The relevant monitoring system checks:

the respective solenoid valve for short circuit andopen circuit via the output stages in the PCM (basedon the power consumption of the solenoid valve).

Vehicles with EOBD

A faulty EGR or wastegate control solenoid valve hasserious effects on the exhaust gas emissions. Bothcomponents are thus MIL active.



Sensors

Pump control unit

E65507

Location

Mounted on the distributor fuel injection pumpNote: The pump control unit and the distributor fuelinjection pump form a single unit and can consequentlynot be replaced individually during servicing.

Task / function

The pump control unit is equipped with a nine-pinconnector, which connects the pump control unit to thePCM and via which the two control modulescommunicate.

Data is exchanged via the CAN data bus as well as viahard-wired lines.

The PCM transmits the data for the injected fuel quantityand the injection timing to the pump control unit. Thepump control unit then actuates the high-pressuresolenoid valve in the distributor fuel injection pump.There is a fuel temperature sensor located in the baseof the pump control unit. The fuel temperature measuredby the sensor is used by the pump control unit tocalculate the fuel density and thus to adapt the injectedfuel quantity required by the PCM.

In order to actuate the high-pressure solenoid valve andthe timing device solenoid valve precisely, thedistributor fuel injection pump also has a rotational angle

sensor, which determines the exact angular position ofthe distributor shaft and transmits it to the pump controlunit.

The pump control unit is cooled with fuel that runsthrough a channel under the pump control unit housing.

Note: Make sure that no electrostatic discharge canoccur before touching the pump control unit connectorsocket. A spark discharge can lead to failure of thecontrol module.

Effects of faults

The engine is stopped or can no longer be started in theevent of the following pump control unit faults:

faulty microprocessor,

CAN communication,

supply voltage,

monitoring of the electrical pump components.

Engine power output is reduced in the event of:

faulty fuel temperature signal,

faulty CKP signal from the PCM.

Vehicles with EOBD

Most faults have little or no effect on exhaust gasemissions and are thus not MIL active.

In the event of a faulty CKP signal from the PCM,control is impaired to such an extent that the exhaustemission limits are exceeded; this is therefore an MILactive fault.


ActuatorsLesson 2 Distributor Type Fuel InjectionSystems

High-pressure solenoid valve

E65508

8

1 2

7 6 5 34

Pump control unit1

PCM2

Permanent magnet3

Coil4

Solenoid armature5

Valve needle6

Closing direction7

Valve seat8

Location

Integrated in the distributor fuel injection pump

Task / function

The high-pressure solenoid valve is located centrally inthe distributor head of the injection pump, whereby thevalve needle projects into the distributor shaft androtates synchronously with it.

The high-pressure solenoid valve is closed (energized)or opened (de-energized) by the pump control unit.

The closing time determines the delivery time of thehigh-pressure pump. The injected fuel quantity canthus be metered precisely.

Timing device solenoid valve

E65509

1

2

3

4

5

Timing device1

Timing device solenoid valve2

Valve needle3

Fuel feed from fuel tank4

Transfer pump (vane-type pump)5

Location

On the underside of the distributor fuel injection pumpin the fuel discharge channel of the timing device

Task / function

Rapid cyclical actuation of the valve needle causes thetiming device solenoid valve to function as a variablerestrictor.

It can thus constantly influence the control pressure sothat the timing device can assume any position betweenthe advance and retard positions.



Actuators

E65510

1

2 3 4 5

6

78

Restriction bore1

Valve body2

Valve body3

Solenoid armature4

Electrical connector5

Mounting flange6

Solenoid coil7

Valve needle8

The pump control unit controls the timing device pistonvia the timing device solenoid valve, which iscontinually actuated via PWM signals.

The duty cycle determines the flow rate.

The flow rate is varied such that the timing devicereaches its desired position.

Rotational angle sensor

Rotational angle sensor in the VP44

E65511

Location

Integrated in the distributor fuel injection pump

Task / function

The rotational angle sensor rotates on a bearing ring,which is fixed to the roller ring (VP30)/cam ring (VP44)and the timing device.

The rotational angle sensor is located on a rotatingmounting because it needs to generate its signal relativeto the angular position of the cam ring (VP30)/rollerring (VP44).



E65512

7

1

6

2

3

4

5

Flexible conducting film1

Rotational angle sensor2

Rotating bearing ring3

Pulse generation wheel (fixed to the drive shaft)4

Drive shaft5

Roller ring/cam ring/timing device connection6

Gap in the teeth7

The pulse for the rotational angle sensor is generatedby a pulse generation wheel which is fixed onto thedrive shaft. It has four gaps in the teeth evenlydistributed around its circumference (the four gapscorrespond to the number of cylinders in the engine).A rotational angle sensor scans the sequence of teethand gaps.

The rotational angle sensor generates its signal relativeto the angular position of the roller ring/cam ring. Forthis reason, it is located on a rotating mounting on thedrive shaft of the distributor fuel injection pump androtates with the roller ring/cam ring as the timing devicemoves.

For adjustment of the injection timing via the timingdevice, the roller ring/cam ring and consequently therotational angle sensor is rotated in the "advance" or"retard" direction.

The signal from the rotational angle sensor is transmittedvia a flexible conductor film to the pump control unitand then used for the following tasks:

measurement of the current rotational speed of thedistributor fuel injection pump,

determination of the current angular position,

determination of the current position of the timingdevice.



Actuators

The current speed of the distributor fuel injection pumpis one of the input variables for the pump control unitof the distributor fuel injection pump. The pump controlunit uses it to determine the actuation time of thehigh-pressure solenoid valve and the duty cycle for thetiming device solenoid valve.

The designated injection quantity determines theactuation time of the high-pressure solenoid valve. Thecurrent angular position defines the actuation timesfor the high-pressure solenoid valve.

Angular precision is required for the actuation to ensurethat both the opening and the closing of thehigh-pressure solenoid valve occur at the correct camlift. Precise actuation ensures that the start of injectionand the injected fuel quantity are correct.The precise angular position is determined bycomparison of the signals from the CKP sensor and therotational angle sensor.

The current position of the timing device, which isrequired for adjustment of the injection timing, is alsodetermined by comparing the signals from the CKPsensor and the rotational angle sensor.



Fuel metering calculations

Diesel engines normally run without the use of a throttlevalve and therefore always operate with an excess ofair.

The torque and power output of the diesel engine areonly changed in the amount of fuel that is madeavailable (injected fuel quantity).Two different strategies are used when calculating thefuel metering:

engine starting,

engine running.

Starting fuel quantity

E65513

1

2

6

3

5

4

Calculation variables when the engine is startedFuel injector nozzle1VP30/VP442

Injected fuel quantity signal3PCM4

CHT sensor5

CKP sensor6

The injected fuel quantity is calculated based on theengine temperature and the engine speed duringstarting. The starting fuel quantity is delivered from thetime the ignition is switched on until a specific minimumengine speed is reached. The driver has no influence onthe starting fuel quantity via the accelerator pedal.

Driving

E65514

2

3

4

56

1

Calculation variables with engine runningFuel injector nozzle1VP30/VP442

Injected fuel quantity signal3PCM4

APP sensor5

CKP sensor6

In normal driving mode, the injected fuel quantity iscalculated from the following main variables:

APP

Engine speed

In addition, the calculation of the injected fuel quantityis influenced by other variables (correction variables),such as engine temperature and boost pressure.



Strategies

Calculation of idle speed/accelerator pedalactuation

E47860

1 2

6

3 45

Calculation of accelerator pedal actuation1

Judder damper2

Calculation unit3

Limiter4

Signal to the injection pump5Idle speed calculation6

While the engine is running, the PCM uses one of thefollowing two calculations as a basis for fuel metering:

idle speed,

accelerator pedal actuation.

Both calculations are performed continuously in paralleland independently of each other.

The values calculated from idle speed and acceleratorpedal actuation are compared with each other by acalculation unit.

This calculation unit then decides which calculation(idle speed or accelerator pedal actuation) should beused as the output signal for the injection pump. Thecalculation unit always chooses the larger value for theinjected fuel quantity.Example: Engine cold the idle speed calculationyields an idle speed of 1,200 rpm and an injected fuelquantity of 7 mg. There is minimal actuation of theaccelerator pedal, whereby the calculation of theaccelerator pedal actuation allows for an injected fuel

quantity of 6 mg. As the value from the accelerator pedalactuation calculation is lower than the result for the idlespeed calculation, the idle speed calculation has higherpriority. As soon as the accelerator pedal actuationcalculation specifies a higher injected fuel quantity(further actuation of the accelerator pedal) than the idlespeed calculation (accelerator pedal actuation calculation> 7 mg), the accelerator pedal actuation calculationapplies.

Control of the fuel limitation quantity

As the diesel engine works with quality-dependentcontrol (no throttle plate; torque is controlled exclusivelyvia the injected fuel quantity), the fuel quantity requestedby the driver or the physically-possible fuel quantitymust not always be injected.This can have the following reasons:

excessively high exhaust emissions,

mechanical overloading of components owing tohigh torque or overspeed,

thermal overload owing to excessively high coolant,oil or turbocharger temperatures.

The characteristic maps for fuel metering in the PCMare programmed such that they always comply with therequirements mentioned above.

Judder damper

E47861

2

3

4

1

5


StrategiesLesson 2 Distributor Type Fuel InjectionSystems

Sudden actuation of acceleratorEngine speed.1

Abrupt actuation of accelerator pedal (driverdemand)

2

Engine speed curve without active judderdamping

3

Engine speed curve with active judder damping4Time5

There is a so-called software filter between theaccelerator pedal calculation and the calculation unit.

Sudden actuation or release of the accelerator pedalresults in a major change in the injected fuel quantityrequirements and therefore in the torque output.

Owing to this abrupt load change, unpleasant jerkingof the powertrain is caused in the elastic mountings(engine speed fluctuations.These are reduced by the judder damper as follows: comparatively less fuel is injected when the engine

speed is increasing,

more fuel is injected when the engine speed isdecreasing.

In addition, the software filter prevents an abrupt dropin engine speed during gear shifting.

Idle speed control

The fuel consumption at idle is mainly determined byidle speed and efficiency.

It is advantageous to have as low an idle speed aspossible, as idling is of considerable importance whendriving in dense traffic (for minimizing fuelconsumption).However, the selected idle speed must be sufficient toensure that, under any conditions (e.g. when the airconditioning is switched on, or the vehicle electricalsystem is heavily loaded), it will not drop so low thatthe engine starts to run roughly or stalls.

To regulate the idle speed, the injected fuel quantity isvaried by the idle speed controller until the measuredactual engine speed is the same as the specified targetengine speed.

Here, the target engine speed and the controlcharacteristic are influenced by the CHT.

Other variables are:

road speed (engine speed compensation system), generator control (smart charging), can increase the

idle speed,

speed control.

Idle speed control when speed control isactivated

Example: Vehicle is traveling in 5th gear at a speed of100 km/h and an engine speed of 2,500 rpm. Underthese conditions, the speed control is then activated.

Of the previously mentioned variables, it is the idlespeed calculation (idle speed control) that will determinethe quantity of injected fuel required to maintain thedesired speed.

Smooth-running control (cylinderbalancing)In addition to the previously described external loadmoments, there are also combustion quality phenomenaand internal friction moments which need to be balancedout. These change slightly, but continuously, over theentire service life of the engine.

In addition, the individual cylinders do not generate thesame level of torque for the entire service life of theengine. The reason for this are the mechanical tolerancesand changes which occur during the service life of theengine. All this could result in a rough-running engine,particularly at idle.



Strategies

The smooth-running control system calculates theaccelerations of the crankshaft via the CKP sensor aftereach combustion process and compares them.

Using the differences in engine speed as a basis, theinjected fuel quantity for each cylinder is adjustedindividually so that all the cylinders make as equal acontribution as possible to the torque produced.

Switching off the engine

Because of the way the diesel engine works, the enginecan only be switched off by interrupting the fuel supply.

In the case of fully electronic engine management, thisis done by the PCM specifying: injected fuel quantity= 0. The high-pressure solenoid valve is therefore nolonger actuated and the engine is switched off.

Fuel delivery

E65515

3 42

5

6

7

8

1

Profile of the cam plate/cam ring of the fuelinjection pump

1

PCM signal to the high-pressure solenoid valve2

Signal for pre-injection3Signal for main injection4High-pressure solenoid valve closed5

High-pressure solenoid valve opened6

Stroke of nozzle needle of fuel injector nozzle7Time8

Electrically controlled pre-injection is used with theVP30/VP44 fuel injection system in the Ford Mondeo.Pre-injection is, alongside conventional two-stageinjection (two-spring nozzle carrier principle), additionalpre-injection that is controlled by the fuel injectionpump.

With two-stage injection the two injection stages havean overlap, which is regulated solely by the injectornozzle (two-spring nozzle carrier). The valve needle ofthe high-pressure solenoid valve in the fuel injectionpump is only actuated once in this case.

With pre-injection, two-spring nozzle carriers are alsoused. In this case, however, a small quantity of fuel isinjected a few milliseconds in advance (pre-injection).Main injection takes place a few milliseconds later. Forthis purpose, the valve needle of the high-pressuresolenoid valve in the fuel injection pump isactuatedtwice during one cam lift.



Control of the injected fuel quantity (2001Mondeo only)

E65516

1

4

3

2

PCM1

Pre-injected and main injected fuel quantity2High-pressure solenoid valve3

Pump control unit4

The injected fuel quantity and the injection timing arecalculated by the PCM by evaluating the various inputvariables (e.g. accelerator pedal position, engine speed,boost pressure, etc.). The PCM sends a signal for aspecified total injected quantity and the injection timingto the pump control unit.

The pump control unit splits the incoming signal intopre-injected fuel quantity and main injected fuel quantityand actuates the high-pressure solenoid valveaccordingly.

The pre-injected fuel quantity is dependent on the enginespeed and/or the engine load. As the engine speed/engineload increases, the interval between pre-injection andmain injection is increased accordingly by continuouslyreducing the pre-injected fuel quantity.

E65517

1 2a

Injection signal for the high-pressure solenoid valveInterval between pre-injection and main injectionaInjected fuel quantity for pre-injection1Injected fuel quantity for main injection2

NOTE: The range in which pre-injection can be carriedout is restricted by physical/mechanical limits. Thismeans that pre-injection is deactivated after a specificengine speed and/or engine load has been reached.

Shortly before pre-injection is deactivated, maininjection is advanced. This helps to achieve a smoothertransition.



Strategies

Synchronization of the fuel injection pump

E65519

12

3

4

5

8

9

6

7

CKP sensor1

PCM2

Monitoring signal from the pump control unit3

Missing tooth in the sensor wheel of therotational angle sensor

4

Rotational angle sensor5

Fuel injection pump with pump control units6CAN data bus (injected fuel quantity, injectiontiming)

7

CKP signal8

Fuel injection pump relay9

The fuel injection pump is installed in a fixed position.This means that fuel injection timing cannot be adjustedby fuel injection pump rotation.

Mechanical tolerances (elasticity of drive chain/timingbelt as well as material tolerances) therefore requiresynchronization of the system.



To do this, the PCM transmits the incoming CKP signalto the pump control unit on the fuel injection pump. Thepump control unit compares the CKP signal with theincoming signal from the rotational angle sensor. Signaldeviations are stored by the pump control unit and takeninto account when transmitting the injection timing.

Safety function

The pump control unit of the fuel injection pump ismonitored for correct operation by the PCM. The pumpcontrol unit sends a monitoring signal to the PCM every50 milliseconds.

In the event of signal deviations or signal failure, thePCM cuts off the power for the fuel injection pumprelay and therefore for the pump control unit, and theengine is switched off.

Due to their high priority, both the monitoring signaland the CKP signal are transmitted from the PCM tothe pump control unit via a hard-wired line.

Other data exchanged between the PCM and the pumpcontrol unit is transmitted via the CAN data bus.

Configuration of the pump control unit with thePCM

The pump control unit and the PCM are matched to oneanother with regard to engine management andimmobilizer. This means that following replacement ofthe fuel injection pump, the new pump control unit mustbe configured with the PCM and vice versa.Configuration must be performed using WDS (Worldwide Diagnostic System).



Strategies

EGR system

E47869

2

85

1

9

7

4

3

6

10

EGR solenoid valve1

MAF sensor (variable-geometry turbochargeronly)

2

PCM3

Oxidation catalytic converter4

Turbocharger.5

EGR valve6

Vacuum pump7

Position sensor in the EGR valve (only withturbochargers with fixed turbine geometry)

8

Charge air cooler (not on all versions)9EGR cooler (not on all versions)10

When turbochargers are used (they are deployed on allthe diesel engines described here), the temperatures inthe combustion chamber rise along with compressionand combustion power.

Combustion temperatures are increased even further bythe use of the direct injection process. Both result in theincreased formation of NOX in the exhaust gas.



In order to keep this NOX content in the exhaust gaswithin required limits, an EGR system is used.

In the part load range, exhaust gas recirculation isachieved by mixing the exhaust gases with the intakeair. This reduces the oxygen concentration in the intakeair. In addition, exhaust gas has a higher specific heatcapacity than air and the proportion of water in therecirculated exhaust gas also reduces the combustiontemperatures. These effects lower the combustiontemperatures (and thereby the proportion of NOX) andalso reduce the amount of exhaust gas emitted.

The quantity of exhaust gas to be recirculated isaccurately determined by the PCM. An excessiveexhaust gas recirculation rate would lead to an increasein diesel particulate, CO and HC emissions due to lackof air.

For this reason, the PCM requires feedback on thequantity of exhaust gas recirculated. The two differentsystems used in this case are distinguished by thefollowing components:

position sensor in the EGR valve (on engines witha wastegate-controlled turbocharger),

MAF sensor (on engines with variable-geometryturbocharger),

On both systems the EGR valve is vacuum-actuated bythe EGR solenoid valve. The duty cycle with which theEGR solenoid valve is actuated by the PCM determinesthe vacuum applied at the EGR valve.

System with position sensor in the EGR valve

The position sensor in the EGR valve signals the currentposition of the EGR valve to the PCM. From this, thePCM can determine the quantity of exhaust gas currentlybeing recirculated, thus forming a closed control loop.

System with MAF sensor

The quantity of exhaust gas recirculated when the EGRvalve opens has a direct influence on the MAF sensormeasurement.

During exhaust gas recirculation, the reduced air massmeasured by the MAF sensor corresponds exactly tothe value of the recirculated exhaust gases. If thequantity of recirculated exhaust gas is too high, thedrawn in air mass drops to a specific limit. The PCMthen reduces the proportion of recirculated exhaust gas,thus forming a closed control loop.

Boost pressure control

In diesel engines with turbochargers, the air is fed tothe engine with positive pressure. This increases the airmass in the engine cylinder, which, along with acorrespondingly higher fuel quantity, leads to aincreased torque and power at the same swept volume.

As turbochargers achieve the necessary boost pressureat low engine speeds, any further pressure increase mustbe avoided by means of boost pressure control.

Given the constantly more stringent exhaust emissionslimits defined by law, it is also necessary to optimallyadjust the fuel quantity for all operating conditions.



Strategies

Boost pressure control with wastegate control valve

E65887

4

7

1

2

3

5

86

MAP sensor1

IAT sensor2

Charge air cooler (not on all versions)3Compressor wheel4

Turbocharger.5

PCM6

Turbine7

Wastegate control valve8

At higher speeds or higher engine loads, a partial streamof the exhaust gas is fed into the exhaust system pastthe turbine wheel via a wastegate control valve. Thesplitting of the exhaust gas stream prevents a furtherincrease in turbocharger speed, whereby boost pressuregeneration is restricted by the compressor wheel.

The boost pressure actual value is measured via theMAP sensor. The required value depends upon theengine speed and the injected fuel quantity as well asthe IAT correction factor.

In the event of a malfunction of the boost pressurecontrol system, engine power is reduced via the fuelmetering system.



Boost pressure control with variable-geometry turbocharger

E65888

5

9

1

2

3

4

6

7

10 8


MAP sensor2

IAT sensor3

Charge air cooler (not on all versions)4Compressor wheel5

Turbocharger.6

Vacuum unit for guide vane adjustment7PCM8

Turbine9

Vacuum pump10

On a variable-geometry turbocharger, the boost pressureis regulated by adjusting the guide vanes. The optimumboost pressure can therefore be set for every operatingcondition.

The boost pressure actual value is measured via theMAP sensor. The required value is dependent on theengine speed and the injected fuel quantity as well asthe IAT and BARO correction factors.

When a control deviation occurs, the guide vanes of thevariable-geometry turbocharger are adjusted via thewastegate control solenoid valve.

In the event of a malfunction, engine power output isreduced by means of the fuel metering.



Strategies

Data exchange

E65015

1 2

34

1 2

34

Transmission control module1

Instrument cluster2

PCM3

ABS/stability assist control module4

The PCM communicates with other control modules(ABS/stability assist, automatic transmission) via theCAN data bus system.

This is used to transmit the data and setpoint valuesrequired for operation and fault monitoring.

On the CAN data bus, the data is transmitted serially,i.e. the information is sent simultaneously andconsecutively on two lines.

All the connected control modules are equipped with aserial CAN interface and can therefore send and receivedata via the CAN data bus line.

External intervention into the injected fuelquantity

In an external intervention into the injected fuel quantity,the injected fuel quantity is influenced by anothercontrol unit (for example traction control).

The PCM receives the information regarding necessaryinterventions via the CAN data bus.

This CAN signal informs the PCM whether and howmuch the engine torque and consequently the injectedquantity needs to be changed.

PCM fault strategy

E48114

12 3

456

78

PCM connector1

Microprocessor2

RAM3

EEPROM4

PATS5

Power supply relay6

Fuse7

Battery8

NOTE: DTCs and adaptation data can be deleted withthe aid of WDS.

NOTE: The PCM has a continuous voltage connectionto the battery. This is used, among other things, toactivate the PATS LED.

To store DTCs and other data, the PCM uses theEEPROM memory on diesel engines.

The EEPROM memory is a non-volatile memory(constant value memory) which means that the datacontained in it is retained even if the supply voltage isinterrupted (e.g. if the battery is disconnected).



During driving, all new trouble codes and engineadaption data (e.g. fuel adaption data) are initially storedin the RAM of the PCM.

This data is transferred to the EEPROM data memoryafter the engine is switched off and at specified intervalsduring operation. To ensure this happens, the powersupply relay remains activated for a further 1.2 secondsafter the ignition is switched off (power latch).After the ignition is switched on, the DTCs stored inthe EEPROM are transferred to the RAM memory.

EOBD

General

E66152

From 1 January 2003 or from 1 January 2004, the EOBDwas implemented in diesel vehicles as follows:

From 1 January 2003:

for diesel vehicles newly introduced on themarket.

From 1 January 2004:

for all newly registered diesel vehicles.

This means that from these dates onwards, all dieselvehicles below a permissible total vehicle weight of2,500 kg can only be registered if they feature the EOBDsystem.

The following engines with distributor fuel injectionpump systems are affected by the EOBD:

1.8L Endura-DI (Kent) diesel engine with VP30 (55and 66 kW) in the 1999 Focus,

2.0L Duratorq-DI (Puma) diesel engine with VP30(66 kW) in the 2001 Mondeo.

The EOBD system does not use any additional sensorsor actuators to individually measure pollutants in theexhaust emissions.

The EOBD system is integrated into the software of thePCM and uses the existing sensors and actuators of theengine management system.

With the aid of these sensors, actuators and specialsoftware, systems and components significant foremissions are continually checked during the journeyand exhaust emissions calculated accordingly.

Components significant for emissions are checked withthe so-called monitoring system.

With the introduction of EOBD for European Ford dieselengines, this comprises the following monitoringsystems for distributor fuel injection pump systems: monitoring of components significant to emissions

(Comprehensive Component Monitors =CCM), monitoring of the EGR system,

Monitoring system for components significantfor exhaust emissions (CCM)

The monitoring system for components significant foremissions (CCM) continually checks to see if the sensorsand actuators significant for emissions are operatingwithin the specified tolerances when the engine isrunning.



Strategies

If a sensor or actuator is outside the tolerance range,this is recognized by the monitoring system and a DTCis stored in the data memory.

Monitoring of the EGR system

The operation of the EGR system is monitored toidentify faults that will lead to increased exhaustemissions and may exceed the EOBD threshold values.

In this system check it is not the components of the EGRsystem themselves that are monitored, but rather theactual EGR quantity.

MIL

E48311

The MIL is located in the instrument cluster and showsan engine icon (international standard).The MIL will warn the driver that the EOBD systemhas detected an emissions-related fault in a componentor system.

If an emissions-related fault is detected and if this faultis confirmed during the third driving cycle, the MIL isswitched on.

Illumination of the MIL ensures that a fault is recognizedin time. The defect can be repaired in good time and theemission of exhaust gas with high levels of pollutantsis avoided.

Freeze frame data

When an emissions-related fault occurs for the first time,a fault log containing the freeze frame data is createdin the PCM. Freeze frame data may be:

vehicle speed,

CHT,

engine speed,

engine load state,

distance traveled since the fault was registered forthe first time.

The freeze frame data can be read out using WDS orwith a generic scan tool and thus be used as support fordiagnostics work.

Fault detection and storage

A fault occurring for the first time is labeled as asuspected fault (pending code) and is stored in the datamemory.

If the fault is not confirmed in the next check, it iserased.

If it is confirmed during the third drive cycle, thesuspected fault is automatically converted into aconfirmed fault (continuous code). The freeze framedata does not change; it remains the same as when thefault first occurred.

The MIL only illuminates when the fault has been storedas a confirmed fault.

If the fault does not recur in the course of threeconsecutive driving cycles, the MIL extinguishes in thefourth driving cycle. However, the DTC will remainstored in the data memory.

A DTC is deleted from the fault memory after 40warm-up cycles if the fault has not occurred again duringthis time.



If a faulty signal is detected during a journey and thecorresponding DTC is stored, all the checks in whichthis signal is required as a reference value, will beinterrupted. This prevents follow-up faults from beingstored.

Drive cycle

A drive cycle commences when the engine starts (enginecold or hot) and ends when the engine is switched off.Depending on the complexity of the fault, themonitoring period may vary:

For simple electrical faults, a monitoring period ofless than five minutes is sufficient.

When monitoring the EGR system, where differentoperating conditions are required to complete thetest, the test can take up to around 20 minutes.

Warm-up cycle

A warm-up cycle starts when the engine is started, atwhich point the coolant temperature must be at least 22C, and ends as soon as the coolant temperature exceeds70 C.



Strategies

Overview of the fuel system

E65489

A

C

B

2

3

4

6

7

8

5

1

Fuel returnA

Fuel injection lineBFuel supplyC

Fuel injector nozzle1Pump control unit2

Distributor fuel injection pump VP30/VP443

Fuel filter4

Fuel cooler (VP44 only)5Auxiliary fuel pump (VP44 only)6Fuel tank7

PCM8


Fuel systemLesson 2 Distributor Type Fuel InjectionSystems

Fuel injectors

E65490

13

4

A B

2

Fuel injector nozzle 1.8L Endura-DI (Kent)diesel engine

A

Fuel injector nozzle 2.0L/2.4L Duratorq-DI(Puma) diesel engine

B

Sealing ring1

Retainer2

Locking sleeve3

Sealing ring4

The fuel injector nozzles of these fuel injection systemsfunction according to the two-spring nozzle carrierprinciple.

Fuel injector nozzles from different manufacturers areused depending on the vehicle and engine version:

Bosch:1.8L Endura (Kent) diesel engine with VP30(Ford Focus), 2.0L Duratorq-DI (Puma) diesel enginewith VP30/44 (Ford Mondeo),

Delphi: 2.0L Duratorq-DI (Puma) diesel engine withVP30 (Ford Transit), 2.4L Duratorq-DI (Puma) dieselengine with VP30/44 (Ford Transit)

In the 1.8L Endura-DI, the fuel injector nozzles areinserted and fastened in the cylinder head, while thefuel injector nozzles in the 2.0L and 2.4L Duratorq arescrewed into the cylinder head with a locking sleeve.



Fuel system

Function of the two-spring nozzle carrier

E65016

1

2

3

A B C

4

5

Injector nozzle closedAPre-injectionBMain injectionCSpring 11

Spring 22

Stroke 13

Stroke 1 + stroke 24

Stroke 25

The two-spring nozzle carrier principle makes asignificant contribution towards smoother combustion.

The two-spring nozzle carrier allows fuel to be injectedin two stages.

The fuel injector nozzle is designed as a five-holenozzle.

The nozzle carrier contains two springs of differentstrengths.


Fuel systemLesson 2 Distributor Type Fuel InjectionSystems

The springs are configured in such a way that the nozzleneedle is only lifted against the force of the first springat the start of injection.A small quantity of fuel is pre-injected through theresulting small gap at low pressure. This pre-injectionensures a gradual increase in the combustion pressureand creates the ignition conditions for the main fuelquantity.

Due to the fact that the fuel injection pump deliversmore fuel than can flow through the small gap, thepressure in the injector nozzle increases. The force ofthe second spring is overcome and the nozzle needle islifted further. Main injection now takes place at a higherinjection pressure.

Injection lines

E65491

NOTE: The injection lin

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