Technical service training diesel injection and engine management systems

Technical Service Training

Diesel Injection and Engine

Management Systems

Common Rail Systems

CG 8258/S en 01/2008

TC304 3 060H

To the best of our knowledge, the illustrations, technical information, data and descriptions in this issue were correct at the time

of going to print. The right to change prices, specifications, equipment and maintenance instructions at any time without notice

is 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,

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can be accepted for any inaccuracies in this publication, although every possible care has been taken to make it as complete and

accurate as possible.

Copyright ©2008

Ford-Werke GmbH

Service training programs D-F/GT1 (GB)

More stringent exhaust and noise emission standards and calls for lower fuel consumption continue to place new

demands on the fuel injection and engine management systems of diesel engines.

In order to satisfy these requirements, the injection system must inject the fuel at high pressure into the combustion

chamber to provide good mixture preparation and, at the same time, meter the injected fuel quantity with the highest

possible accuracy. The common rail system offers good potential for development, which is of particular significance

both now and in the future. By separating the pressure generation process from the injection process, the optimum

injection pressure is always available for the injection process, regardless of engine speed.

Modern engine management systems ensure that the fuel injection timing and injected fuel quantity are exactly

calculated and delivered to the engine cylinders by the fuel injectors.

The following common rail systems are currently installed in Ford vehicles:

– Bosch common rail system,

– Siemens common rail system,

– Denso common rail system.

Another big step towards achieving cleanliness in diesel engines is the newly developed diesel particulate filter

system. This system helps reduce micro-fine diesel particulates by up to 99%.

Completion of the eLearning program "Diesel Fuel Injection and Engine Management Systems" is a prerequisite

for the study of this Student Information.

This Student Information is divided into lessons. At the end of each lesson there is a set of test questions that are

designed to monitor the student's progress. The solutions to these 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. Repairs

and adjustments MUST always be carried out according to the instructions and specifications in the workshop

literature. Please make full use of the training offered by Ford Technical Training Courses to gain extensive

knowledge of both theory and practice.

Service Training (G1008812) 1

Preface

PAGE

Preface............................................................................................................................... 1

Lesson 1 – General Information

Overview of the systems................................................................................................................................................... 6

Introduction....................................................................................................................................................................... 10

Injection characteristics..................................................................................................................................................... 11

Torque................................................................................................................................................................................ 13

Emission Standard IV with or without DPF...................................................................................................................... 13

Cleanliness when working on the common rail system.................................................................................................... 13

Test questions................................................................................................................................................ 14

Lesson 2 – Fuel System

Overview........................................................................................................................................................................... 15

Low-pressure system.................................................................................................................................... 20

General.............................................................................................................................................................................. 20

Bosch common rail system........................................................................................................................... 21

Fuel filter........................................................................................................................................................................... 21

Overview of the high-pressure system.............................................................................................................................. 25

Fuel pump.......................................................................................................................................................................... 27

Fuel rail (common rail)...................................................................................................................................................... 33

High-pressure fuel lines..................................................................................................................................................... 33

Fuel injectors (general)...................................................................................................................................................... 33

Solenoid valve-controlled fuel injectors............................................................................................................................ 34

Piezo-controlled fuel injectors........................................................................................................................................... 37

Siemens common rail system....................................................................................................................... 42

Fuel filter........................................................................................................................................................................... 42

Overview of the high-pressure system.............................................................................................................................. 43

Fuel pump.......................................................................................................................................................................... 44

Fuel rail and high-pressure fuel lines................................................................................................................................ 47

Fuel injectors..................................................................................................................................................................... 48

Denso common rail system........................................................................................................................... 53

Fuel filter........................................................................................................................................................................... 53

Overview of the high-pressure system.............................................................................................................................. 54

Fuel pump.......................................................................................................................................................................... 55

Fuel rail and high-pressure fuel lines................................................................................................................................ 58

Fuel injectors..................................................................................................................................................................... 60

Test questions................................................................................................................................................ 62

2 Service Training

Table of Contents

Lesson 3 – Powertrain Control Module (PCM)

General.............................................................................................................................................................................. 63

Input signals...................................................................................................................................................................... 63

Output signals.................................................................................................................................................................... 63

Diagnosis........................................................................................................................................................................... 64

PCM and peripherals................................................................................................................................... 65

Bosch common rail system................................................................................................................................................ 65

Siemens common rail system............................................................................................................................................ 69

Denso common rail system............................................................................................................................................... 73

Strategies....................................................................................................................................................... 75

Idle speed control.............................................................................................................................................................. 75

Fuel metering calculations................................................................................................................................................. 75

Smooth-running control (cylinder balancing)................................................................................................................... 77

External intervention into the injected fuel quantity......................................................................................................... 77

Controlling fuel injection.................................................................................................................................................. 78

Controlling the fuel pressure............................................................................................................................................. 79

EGR system....................................................................................................................................................................... 81

Boost pressure control....................................................................................................................................................... 83

EOBD............................................................................................................................................................. 86

General.............................................................................................................................................................................. 86

Fault logging and storing................................................................................................................................................... 87

Test questions................................................................................................................................................ 88

Lesson 4 – Sensors

Introduction....................................................................................................................................................................... 89

CKP sensor........................................................................................................................................................................ 89

CMP sensor....................................................................................................................................................................... 91

MAP sensor....................................................................................................................................................................... 92

IAT sensor.......................................................................................................................................................................... 93

MAPT sensor..................................................................................................................................................................... 93

BARO sensor..................................................................................................................................................................... 94

ECT sensor........................................................................................................................................................................ 94

CHT sensor (Kent and Puma diesel engines only)............................................................................................................ 96

Combined IAT sensor and MAF sensor............................................................................................................................ 98

HO2S................................................................................................................................................................................. 99

Turbocharger position sensor (certain versions only)....................................................................................................... 100

Vehicle speed signal.......................................................................................................................................................... 101

APP sensor........................................................................................................................................................................ 102

Service Training 3

Table of Contents

Fuel temperature sensor..................................................................................................................................................... 103

Fuel pressure sensor.......................................................................................................................................................... 104

Engine oil level sensor (2.4L/3.2L Duratorq-TDCi (Puma) diesel engine)...................................................................... 105

Engine oil level sensor (2.2L Duratorq-TDCi (DW) diesel engine)................................................................................. 107

Oil pressure switch............................................................................................................................................................ 109

Stoplamp switch/BPP switch............................................................................................................................................. 109

CPP switch........................................................................................................................................................................ 110

Test questions................................................................................................................................................ 111

Lesson 5 – Actuators

Fuel metering valve........................................................................................................................................................... 112

Fuel pressure regulator...................................................................................................................................................... 114

Fuel injectors (solenoid valve-controlled)......................................................................................................................... 116

Fuel injectors (piezo-controlled)....................................................................................................................................... 118

EGR valve......................................................................................................................................................................... 119

Wastegate control valve (vacuum-controlled systems)..................................................................................................... 121

Intake manifold flap and intake manifold flap solenoid valve (vacuum-controlled systems)........................................... 122

Intake manifold flap actuator motor (1.6L Duratorq-TDCi (DV) diesel engine, Emission Standard IV)........................ 123

Turbocharger variable vane electrical actuator.................................................................................................................. 125

Electric fuel pump (2.2L Duratorq-TDCi (DW) diesel engine only)................................................................................ 128

Test questions................................................................................................................................................ 129

Lesson 6 – Engine Emission Control

Introduction................................................................................................................................................... 130

Pollutant emissions reduction............................................................................................................................................ 130

DPF (general).................................................................................................................................................................... 130

Regeneration of the DPF (general).................................................................................................................................... 131

DPF with fuel additive system..................................................................................................................... 133

Component overview......................................................................................................................................................... 133

DPF.................................................................................................................................................................................... 135

Charge air cooler bypass................................................................................................................................................... 136

Fuel additive system – general.......................................................................................................................................... 138

Components of the fuel additive system........................................................................................................................... 139

Component overview – system control............................................................................................................................. 141

PCM................................................................................................................................................................................... 143

Fuel additive control unit................................................................................................................................................... 143

Fuel additive pump unit..................................................................................................................................................... 144

Tank flap switch................................................................................................................................................................ 145

Exhaust gas temperature sensor(s).................................................................................................................................... 146

4 Service Training

Table of Contents

DPF differential pressure sensor ...................................................................................................................................... 147

Intake manifold flap actuator motors (Bosch system only).............................................................................................. 148

Charge air cooler bypass flap actuator motor (Bosch system only).................................................................................. 148

Intake manifold flap and charge air cooler bypass flap solenoid valves (Siemens system).............................................. 150

Coated diesel particulate filter (DPF)......................................................................................................... 151

Overview of the DPF......................................................................................................................................................... 151

Passive regeneration.......................................................................................................................................................... 151

Active regeneration............................................................................................................................................................ 152

Notes on the oil change interval........................................................................................................................................ 152

DPF regeneration indicator (2006.5 Transit only)............................................................................................................. 153

Intake manifold flap.......................................................................................................................................................... 153

Components of the engine emission control system......................................................................................................... 154

Exhaust gas temperature sensor(s).................................................................................................................................... 155

DPF differential pressure sensor ...................................................................................................................................... 155

Intake manifold flap position sensor (vacuum-controlled systems).................................................................................. 156

Intake manifold flap unit................................................................................................................................................... 157

Fuel vaporiser system................................................................................................................................... 158

General.............................................................................................................................................................................. 158

Fuel vaporiser system fuel pump....................................................................................................................................... 159

Fuel vaporiser.................................................................................................................................................................... 160

Test questions................................................................................................................................................ 161

Answers to the test questions........................................................................................... 162

List of Abbreviations........................................................................................................ 163

Service Training 5

Table of Contents

Overview of the systems

Bosch common rail system with "solenoid valve-controlled" fuel injectors

E51104

6 (G1009902) Service Training

Lesson 1 – General Information

Bosch common rail system with "piezo-controlled" fuel injectors

E96077

Service Training (G1009902) 7

Lesson 1 – General Information

Siemens common rail system

E53583

8 (G1009902) Service Training

Lesson 1 – General Information

Denso common rail system

E69955

Assignment of the common rail systems to the engines

Engine Bosch Siemens Denso

1.4L Duratorq-TDCi (DV) X

diesel

1.6L Duratorq-TDCi (DV) X

diesel

1.8L Duratorq-TDCi (Kent) X*

diesel

Service Training (G1009902) 9

Lesson 1 – General Information

Engine Bosch Siemens Denso

2.0L Duratorq-TDCi (DW) X

diesel

2.2L Duratorq-TDCi (DW) X

diesel

2.2L Duratorq-TDCi X*

(Puma) diesel

2.4L Duratorq-TDCi X*

(Puma) diesel

3.2L Duratorq-TDCi X

(Puma) diesel

* Older versions are equipped with the Delphi common rail system. The Delphi common rail system is not part of this Student Information.

Introduction

Increasingly higher demands are being placed on modern

diesel engines. The focus today is not only on exhaust

emissions but also on increasing environmental

awareness and the demand for increasingly better

economy and enhanced driving comfort.

This requires the use of complex injection systems, high

injection pressures and accurate fuel metering by fully

electronically-controlled systems.

The high injection pressures convert the fuel, via the

injector nozzle, into tiny droplets, which, again due to

the high pressure, can then be optimally distributed in

the combustion chamber. This results in less unburned

HC (Hydrocarbon), less CO (Carbon Monoxide) and

fewer diesel exhaust particulates being produced in the

subsequent combustion stage.

In addition, the optimised mixture formation reduces

fuel consumption.

Diesel knock caused by the combustion process of an

engine with direct injection is significantly reduced by

means of additional pilot injection. NOX (Oxides Of

Nitrogen) emissions can also be reduced by using this

method.

In particular, the demands placed upon the injection

system and its regulation are as follows for modern

diesel engines:

• high injection pressures,

• shaping of injection timing characteristics,

• multiple injections,

• values for injected fuel quantity, start of injection

and boost pressure adapted to every operating

condition,

• load-independent idle speed control,

• closed-loop EGR (Exhaust Gas Recirculation),

• low injection timing and injected fuel quantity

tolerances and high degree of precision over the

entire service life,

• possibility of interaction with other systems such as

stability assist, PATS (Passive Anti-Theft System),

• comprehensive diagnostic facilities,

• substitute strategies in the event of faults.

The common rail injection system has a large range

of features to meet these demands.

In common rail injection systems, pressure generation

is separate from the injection process. The injection

pressure is generated independently of engine speed and

injected fuel quantity.

The common rail injection system consists of a

high-pressure pump and a fuel rail (fuel

accumulator/rail). This fuel rail offers constant pressure

for distributing fuel to the electrically-controlled fuel

injectors.

With this type of diesel injection or engine management,

the driver has no direct influence on the injected fuel

quantity. For example, there is no mechanical connection

10 (G1009902) Service Training

Lesson 1 – General Information

between the accelerator pedal and the injection pump.

The injected fuel quantity is determined by various

parameters. These include:

• driver demand (accelerator pedal position),

• operating condition,

• engine temperature,

• effects on exhaust emissions,

• prevention of engine and transmission damage,

• faults in the system.

Using these parameters, the injected fuel quantity is

calculated in the PCM (Powertrain Control Module)

and fuel injection timing and injection pressure can be

varied.

The fuel is metered fully electronically by the PCM.

The fully electronic diesel engine management system

features a comprehensive fail-safe concept (integrated

in the PCM software). It detects any deviations and

malfunctions and initiates corresponding actions

depending on the resulting effects (e.g. limiting the

power output by reducing the quantity of fuel).

Injection characteristics

As already mentioned at the beginning of the lesson,

the exhaust emissions and fuel consumption of an

engine are of great significance. These factors can only

be minimised through precise operation of the injection

system and comprehensive engine management

strategies.

Consequently, the following requirements must be met

by the common rail system:

• The injection timing must be exact. Even small

variations have a significant effect on fuel

consumption, exhaust emissions and combustion

noise.

• The fuel injection pressure is independently adapted

to all operating conditions.

• Injection must be reliably terminated. Calculation

of the injected fuel quantity and the injection timing

is precisely adapted to the mechanical components

of the injection system. Uncontrolled fuel dribble

(e.g. caused by a defective fuel injector) results in

increased exhaust emissions and increased fuel

consumption.

Simple main injection

Needle lift of the fuel injector nozzle and pressure curve

in a cylinder without pilot injection

E64973

1

2

3

4

5

1 Combustion pressure in the cylinder

2 Needle lift

3 TDC (Top Dead Center)

4 Needle lift with simple main injection

5 Crankshaft angle

In the case of diesel engines with a distributor-type

fuel injection pump (e.g. in the Transit 2000.5), fuel

injection takes place via simple main injection.

The fuel is then injected mechanically into the

combustion chamber by the injector nozzles in two

seamlessly integrated stages (two-spring nozzle carrier

principle).

In the pressure curve, the combustion pressure increases

only slightly in the phase before TDC corresponding to

compression, but increases very sharply at the start of

combustion.

The sharp pressure rise intensifies the combustion noise.

Service Training (G1009902) 11

Lesson 1 – General Information

Pilot injection

Needle lift of the fuel injector nozzle and pressure curve

in a cylinder with pilot injection

E64974

1

2

3

4

5

6

1 Combustion pressure in the cylinder

2 Needle lift

3 TDC

4 Needle lift with pilot injection

5 Needle lift with main injection

6 Crankshaft angle

In the case of vehicles with a common rail injection

system, electrically-controlled pilot injection occurs

after a set time prior to the main injection event.

Pilot injection means that a small amount of fuel is

injected into the cylinder prior to the main injection.

The small pilot-injection fuel quantity is ignited, heats

up the upper part of the cylinder and thereby brings it

into an optimum temperature range (preconditioning of

the combustion chamber).

This means that the main injection mixture ignites more

quickly and the rise in temperature and combustion

pressure is less abrupt as a result.

Advantage:

• Continuous build-up of combustion pressure,

resulting in reduced combustion noise.

• Reduction of oxides of nitrogen in the exhaust gas.

Note: As pressure generation and injection are separate

in common rail systems, it is possible to considerably

enhance the range for pilot injection. This has led to a

significant improvement in the running smoothness of

the engine.

With modern fuel injectors, it is also possible to work

with multiple pilot injections. The greater the number

of pilot injections, the lower the noise emissions.

Post-injection (vehicles with DPF (Diesel

Particulate Filter) system)

Needle lift of the injector nozzle with pilot and

post-injection

E51105

1

2

4

5 6

3

1 Needle lift

2 Pilot injection

3 Crankshaft angle

4 Main injection

5 Advanced post-injection

6 Retarded post-injection

For vehicles with a DPF (Diesel Particulate Filter)

system, two post-injections are employed during the

regeneration process, in addition to the pilot and main

injections, depending on the requirements.

Advanced post-injection is initiated in certain

load/speed ranges immediately after main injection.

Fuel is then injected during the on-going combustion.

The main purpose of this advanced post-injection is to

raise the exhaust gas temperature during the regeneration

process of the DPF. In addition, some of the diesel

particulates produced during regeneration are

after-burned.

12 (G1009902) Service Training

Lesson 1 – General Information

Retarded post-injection only occurs shortly before

BDC (Bottom Dead Center) and also serves to raise the

exhaust gas temperature.

In contrast to advanced post-injection, during retarded

post-injection the fuel is not burned, but vaporises due

to the residual heat in the exhaust gas. This exhaust/fuel

mixture is delivered to the exhaust system by the exhaust

stroke.

In the oxidation catalytic converter, the fuel vapour

reacts with the residual oxygen (above a certain

temperature) and burns. This provides sustained heating

of the oxidation catalytic converter, which supports the

regeneration of the DPF.

Torque

In general, diesel engines generate a high torque across

a wide engine speed range. This is achieved through

uniformly good cylinder charging (working without a

throttle plate) and high combustion pressure.

Overtorque function

On some vehicle versions, an overtorque function (also

called an overboost function) is used. This makes it

possible to briefly exceed the maximum specified torque

during rapid acceleration (by about 15 to 35 Nm

depending on the calibration).

The short-term torque increase is an advantage when

overtaking, for example.

The vehicle acceleration is calculated based on the

vehicle speed signal and the CKP (Crankshaft Position)

sensor. During acceleration, the PCM activates the

overtorque function in an engine speed range between

1,700 and 3,500 rpm.

Emission Standard IV with or without

DPF

At the time of going to press, Emission Standard IV

applies in Europe.

In the diesel sector, Emission Standard IV is achieved

using two different methods.

One method consists of reducing exhaust emissions by

means of internal engine measures to the extent that

the prescribed limits are met.

Measures for the reduction of exhaust emissions inside

the engine include, for example:

• further optimised exhaust gas recirculation by means

of an electrically-controlled EGR system with intake

air restriction,

• optimisation of the combustion chamber design and

the injection characteristics.

In addition to the internal engine measures, the second

method employs a DPF system.

The use of the DPF reduces diesel particulate emissions

by up to 99%. This reduction far exceeds the

requirements for the European emission limits of

Emission Standard IV.

It can therefore be deduced that the use of the DPF will

be of great importance with regard to future emission

standards, but is not absolutely necessary for meeting

Emission Standard IV.

Cleanliness when working on the

common rail system

NOTE: Because the components of the high-pressure

fuel system are high-precision machined parts, it is

essential that scrupulous cleanliness is observed when

carrying out any work on the system.

In this regard, refer to the instructions in the current

Service Literature.

Service Training (G1009902) 13

Lesson 1 – General Information