Tài liệu hệ thống nhiên liệu common rail - ford

Curriculum Training
Diesel Injection and Engine Management
Systems
Common Rail Systems
Technical Service Training
CG 8180/S en 12/2005
TC3043048H
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,
mechanical, photocopy, recording, translation or by any other means without prior permission of Ford-Werke GmbH. No liability
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 ©2001
Ford-Werke GmbH
Service training programs D-F/GT1 (GB)
More stringent exhaust and noise emission standards and requirements regarding lower fuel consumption continue
to place new demands on the fuel injection and engine management system 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.
The newly developed engine management system ensures that the fuel injection timing and injected fuel quantity
are calculated exactly, and that the fuel is delivered to the engine cylinders by the piezo-controlled fuel injectors.
The following common rail systems are currently used in Ford vehicles:
– Delphi common rail system,
– 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. The objectives that should be met by working through the lesson
are set out at the beginning of each lesson. At the end of each lesson there is a set of test questions which 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.
1Service Training (G544949)
Preface
PAGE
1Preface .............................................................................................................................
Lesson 1 – General Information
13Objectives ...................................................................................................................................................
14Overview of the Systems ...............................................................................................................................................
17Introduction ....................................................................................................................................................................
18Injection characteristics ..................................................................................................................................................
21Emission Standard IV with or without diesel particulate filter ......................................................................................
21Cleanliness when working on the common rail system .................................................................................................
22EOBD (European On-board Diagnostic) ................................................................................................
22General ...........................................................................................................................................................................
23Fault logging and storing ...............................................................................................................................................
25Engine Emission Control ..........................................................................................................................
25Pollutant emissions reduction ........................................................................................................................................
27Test questions .............................................................................................................................................
Lesson 2 – Delphi-Common Rail System

29Objectives ...................................................................................................................................................
30Overview of the two-module system – system with PCM and separate IDM ...............................................................
32Overview of the single-module system – system with one PCM (IDM integrated in the PCM) ...................................
33Characteristics ................................................................................................................................................................
33Special features ..............................................................................................................................................................
34Service instructions ........................................................................................................................................................
34EEC V powertrain control module PCM (two-module system) ....................................................................................
36IDM (two-module system) .............................................................................................................................................
Service Training2
Table of Contents
37Delphi PCM (single-module system) .............................................................................................................................
38Glow plug control ..........................................................................................................................................................
40Sensors ........................................................................................................................................................
40CKP sensor .....................................................................................................................................................................
41CMP sensor ....................................................................................................................................................................
42MAP/IAT and T-MAP sensor .........................................................................................................................................
43CHT sensor ....................................................................................................................................................................
45MAF sensor ....................................................................................................................................................................
45VSS ................................................................................................................................................................................
46APP sensor .....................................................................................................................................................................
47KS ...................................................................................................................................................................................
47Fuel temperature sensor .................................................................................................................................................
48Fuel pressure sensor .......................................................................................................................................................
48Fuel pressure outside the specified range .......................................................................................................................
49Position sensor in vacuum-operated EGR valve ............................................................................................................
50Position sensor in electric EGR valve ............................................................................................................................
51Switch ..........................................................................................................................................................
51Stoplamp switch/BPP switch .........................................................................................................................................
51CPP switch .....................................................................................................................................................................
52Actuators ....................................................................................................................................................

52Fuel metering valve ........................................................................................................................................................
53Fuel injector solenoid valve ...........................................................................................................................................
55EGR solenoid valve and boost pressure control solenoid valve ....................................................................................
55Intake manifold flap and intake manifold flap solenoid valve .......................................................................................
56Electric EGR valve (certain versions only) ....................................................................................................................
58Electrical turbocharger guide vane adjustment actuator ................................................................................................
3Service Training
Table of Contents
61Strategies ....................................................................................................................................................
61Ignition ON strategy .......................................................................................................................................................
61Engine start strategy .......................................................................................................................................................
64Idle strategy ....................................................................................................................................................................
64Idle speed control ...........................................................................................................................................................
65Fuel metering calculation ...............................................................................................................................................
68Smooth-running control (cylinder balancing) ................................................................................................................
68External fuel quantity intervention ................................................................................................................................
68Controlling fuel injection ...............................................................................................................................................
70Controlling the fuel pressure ..........................................................................................................................................
72EGR system ....................................................................................................................................................................
75Boost pressure control ....................................................................................................................................................
77PCM fault strategy .........................................................................................................................................................
77Monitoring the system ...................................................................................................................................................
79Coated diesel particulate filter .................................................................................................................
79Overview – diesel particulate filter ................................................................................................................................
80Passive regeneration .......................................................................................................................................................
80Active regeneration ........................................................................................................................................................
81Notes on the oil change interval .....................................................................................................................................
82Emission control components ........................................................................................................................................
82Service instructions ........................................................................................................................................................
83Exhaust gas temperature sensors ....................................................................................................................................

83Diesel particulate filter differential pressure sensor .......................................................................................................
85MAP sensor ....................................................................................................................................................................
85Intake manifold flap and intake manifold flap solenoid valve .......................................................................................
86Intake manifold flap position sensor ..............................................................................................................................
Service Training4
Table of Contents
87Fuel System ................................................................................................................................................
87Overview ........................................................................................................................................................................
88General ...........................................................................................................................................................................
89Fuel filter ........................................................................................................................................................................
90Overview – high-pressure system ..................................................................................................................................
91High pressure pump .......................................................................................................................................................
95Fuel rail (common rail) ..................................................................................................................................................
96Excess pressure safety valve ..........................................................................................................................................
97High-pressure fuel lines and leak-off pipes ...................................................................................................................
97Fuel injectors ..................................................................................................................................................................
102Test questions .............................................................................................................................................
Lesson 3 – Bosch-Common Rail System
103Objectives ...................................................................................................................................................
104Overview ........................................................................................................................................................................
105Characteristics ................................................................................................................................................................
105Service instructions ........................................................................................................................................................
106PCM ...............................................................................................................................................................................
107Glow plug control ..........................................................................................................................................................
110Sensors ........................................................................................................................................................
110CKP sensor .....................................................................................................................................................................
110CMP sensor ....................................................................................................................................................................
111MAP sensor ....................................................................................................................................................................
112BARO sensor ..................................................................................................................................................................
112ECT sensor .....................................................................................................................................................................

114Combined IAT sensor and MAF sensor .........................................................................................................................
5Service Training
Table of Contents
115Vehicle speed signal .......................................................................................................................................................
115APP ................................................................................................................................................................................
116Fuel temperature sensor .................................................................................................................................................
116Fuel pressure sensor .......................................................................................................................................................
118Switch ..........................................................................................................................................................
118Oil pressure switch .........................................................................................................................................................
118Stoplamp switch/BPP switch .........................................................................................................................................
118CPP switch .....................................................................................................................................................................
119Actuators ....................................................................................................................................................
119Fuel metering valve (CP3.2) ..........................................................................................................................................
120Fuel metering valve (CP1H) ..........................................................................................................................................
121Fuel injector solenoid valve ...........................................................................................................................................
123Boost pressure control solenoid valve ............................................................................................................................
124EGR valve ......................................................................................................................................................................
125Intake manifold flap servo motor (vehicles with diesel particulate filter) .....................................................................
128Strategies ....................................................................................................................................................
128Regeneration process .....................................................................................................................................................
130EGR system ....................................................................................................................................................................
132Boost pressure control ....................................................................................................................................................
133Controlling the fuel pressure ..........................................................................................................................................
134Other strategies ..............................................................................................................................................................
135Diesel particulate filter with fuel additive system ...................................................................................
135Component overview .....................................................................................................................................................
136Diesel particulate filter ...................................................................................................................................................
138Intercooler bypass ..........................................................................................................................................................
140Fuel additive system – general .......................................................................................................................................
Service Training6

Table of Contents
141System components – fuel additive system ...................................................................................................................
143Component overview – system control ..........................................................................................................................
144Service instructions ........................................................................................................................................................
144Control modules .............................................................................................................................................................
145Fuel additive pump unit .................................................................................................................................................
146Tank flap switch .............................................................................................................................................................
147IAT sensor ......................................................................................................................................................................
147Exhaust gas temperature sensor .....................................................................................................................................
148Diesel particulate filter differential pressure sensor .......................................................................................................
150Intake manifold flap servo motor ...................................................................................................................................
150Intercooler bypass flap servo motor ...............................................................................................................................
152Fuel System ................................................................................................................................................
152Overview ........................................................................................................................................................................
153General ...........................................................................................................................................................................
154Fuel filter ........................................................................................................................................................................
155Overview – high-pressure system ..................................................................................................................................
156High pressure pump .......................................................................................................................................................
162Fuel rail (common rail) ..................................................................................................................................................
163High pressure fuel lines ..................................................................................................................................................
163Fuel injectors ..................................................................................................................................................................
168Test questions .............................................................................................................................................
Lesson 4 – Siemens-Common Rail System
169Objectives ...................................................................................................................................................
170Overview ........................................................................................................................................................................
173Characteristics ................................................................................................................................................................
7Service Training
Table of Contents
173Special features ..............................................................................................................................................................
174Service instructions ........................................................................................................................................................

174PCM ...............................................................................................................................................................................
176Glow plug control ..........................................................................................................................................................
177Sensors ........................................................................................................................................................
177MAP sensor ....................................................................................................................................................................
178IAT sensor ......................................................................................................................................................................
179BARO sensor ..................................................................................................................................................................
180Turbocharger position sensor (certain versions only) ....................................................................................................
180ECT sensor .....................................................................................................................................................................
181CHT sensor (1.8L Duratorq-TDCi (Kent) diesel only) ..................................................................................................
182Combined IAT sensor and MAF sensor .........................................................................................................................
183Vehicle speed signal .......................................................................................................................................................
184APP sensor .....................................................................................................................................................................
185Vacuum-operated intake manifold flap position sensor (certain vehicles with emission standard IV) .........................
185Fuel pressure sensor .......................................................................................................................................................
187Other sensors ..................................................................................................................................................................
188Switch ..........................................................................................................................................................
188Information .....................................................................................................................................................................
189Actuators ....................................................................................................................................................
189Fuel metering valve ........................................................................................................................................................
191Fuel pressure control valve ............................................................................................................................................
194Piezo-electric control of fuel injectors ...........................................................................................................................
196Boost pressure control valve (variable geometry turbocharger, vacuum-controlled) ....................................................
197Electrical turbocharger guide vane adjustment actuator ................................................................................................
199Intake manifold flap and intake manifold flap solenoid valve (vacuum-operated systems) ..........................................
Service Training8
Table of Contents
200Intake manifold flap servo motor (1.4L Duratorq-TDCi (DV) diesel engine, emission standard IV) ...........................
200EGR valve solenoid valve (vacuum-controlled systems) ...............................................................................................
201EGR valve (electrically controlled systems) ..................................................................................................................
204Engine warm-up regulation(only 2.0L Duratorq-TDCi (DW) diesel engine) ......................................

204Note ................................................................................................................................................................................
204Component locations ......................................................................................................................................................
205Principle of operation .....................................................................................................................................................
208Boost pressure control ....................................................................................................................................................
209Controlling the fuel pressure ..........................................................................................................................................
210Other strategies ..............................................................................................................................................................
211Diesel particulate filter with fuel additive system ...................................................................................
211Note ................................................................................................................................................................................
211Component overview .....................................................................................................................................................
212Diesel particulate filter ...................................................................................................................................................
213Intercooler bypass ..........................................................................................................................................................
215Component overview – system control ..........................................................................................................................
216Service instructions ........................................................................................................................................................
216Exhaust gas temperature sensors ....................................................................................................................................
218Intake manifold flap and intercooler bypass flap solenoid valves .................................................................................
220Coated diesel particulate filter .................................................................................................................
220Overview – diesel particulate filter ................................................................................................................................
221Emission control components ........................................................................................................................................
221Service instructions ........................................................................................................................................................
222Intake manifold flap, intake manifold flap position sensor and intake manifold flap solenoid valve ...........................
223Siemens system ...........................................................................................................................................
223Overview ........................................................................................................................................................................
9Service Training
Table of Contents
224General ...........................................................................................................................................................................
225Fuel filter ........................................................................................................................................................................
226Manual pump .................................................................................................................................................................
227High-pressure system – general .....................................................................................................................................
228High pressure pump .......................................................................................................................................................
232Fuel rail (common rail) and high pressure fuel lines .....................................................................................................

234Fuel injectors ..................................................................................................................................................................
239Test questions .............................................................................................................................................
Lesson 5 – Denso-Common Rail System
241Objectives ...................................................................................................................................................
242Overview ........................................................................................................................................................................
243Notes on this lesson ........................................................................................................................................................
243Characteristics ................................................................................................................................................................
244Service instructions ........................................................................................................................................................
244PCM ...............................................................................................................................................................................
246Sensors ........................................................................................................................................................
246MAF sensor ....................................................................................................................................................................
246APP sensor .....................................................................................................................................................................
247Oil level/temperature sensor ..........................................................................................................................................
250Actuators ....................................................................................................................................................
250Electrical turbocharger guide vane adjustment actuator ................................................................................................
251Fuel metering valve ........................................................................................................................................................
252Fuel injector solenoid valve ...........................................................................................................................................
254Fuel system .................................................................................................................................................
254Overview ........................................................................................................................................................................
Service Training10
Table of Contents
255General ...........................................................................................................................................................................
255Fuel filter ........................................................................................................................................................................
256Overview – high-pressure system ..................................................................................................................................
258High pressure pump .......................................................................................................................................................
261Fuel rail (common rail) ..................................................................................................................................................
262Fuel injectors ..................................................................................................................................................................
264Test questions .............................................................................................................................................
265Answers to the test questions ........................................................................................
266List of Abbreviations ......................................................................................................

11Service Training
Table of Contents
Notes
On completing this lesson, you will be able to:
• explain the advantages of the common rail system.
• state the reasons for the use of pilot injection.
• explain what effect pilot injection has on combustion.
• state the reasons for the use of post-injections.
• explain which types of post-injections are used.
• explain the purpose of the EOBD system.
• name the different monitoring systems of the diesel EOBD system.
• explain the fault detection and storage of emission-relevant faults.
• state the reasons for the use of the diesel particulate filter.
13Service Training (G544951)
ObjectivesLesson 1 – General Information
Overview of the Systems
Delphi common rail system
Two-module systemA
Single-module systemB
IDM (Injector Driver Module)1
EEC V-PCM (Powertrain Control Module)2
Delphi PCM3
(G544950) Service Training14
Lesson 1 – General Information
Bosch common rail system
15Service Training (G544950)
Lesson 1 – General Information
Siemens common rail system
(G544950) Service Training16
Lesson 1 – General Information

Denso common rail system
Introduction
Increasingly higher demands are being placed on modern
diesel engines. The focus 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 fewer unburned
17Service Training (G544950)
Lesson 1 – General Information
HC (Hydrocarbon)s, less CO (Carbon Monoxide) and
fewer diesel exhaust particulates being produced in the
subsequent combustion stage.
In addition, the optimized 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 (pilot injection). NOX
(Oxides Of Nitrogen) emissions can also be reduced by
using this method.
Demands for better driving comfort also influence the
requirements placed on today's diesel engines. In
particular, the importance of noise and exhaust
emissions continues to increase. This leads to increased

demands being placed on the injection system and its
control, e. g.:
• high injection pressures,
• shaping of injection timing characteristics,
• pilot injection,
• injected fuel quantity, start of injection and boost
pressure values 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 for the entire
service life,
• options to interact with other systems, such as the
Electronic Stability Program, 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).
The fuel in this fuel rail is at a constant pressure and is
available for distribution to the electrically controlled
fuel injectors.
With this type of diesel injection or engine management
system, the driver does not have a direct influence on

the quantity of injected fuel, because, for example, there
is no mechanical connection between the accelerator
pedal and the injection pump. Here, the injected fuel
quantity is determined by various parameters. These
include:
• driver demand (accelerator pedal position),
• operating state,
• 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 and fuel injection timing and
injection pressure can be varied.
The fuel is metered fully electronically via piezo
elements controlled by the PCM which are located
directly in the fuel injectors.
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
(G544950) Service Training18
Lesson 1 – General Information
be minimized 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 terminated reliably. Calculation
of the injected quantity and the injection timing is
precisely adapted to the mechanical components of
the injection system. Uncontrolled fuel dribble (for
example, caused by a defective fuel injector) results
in increased exhaust emissions and increased fuel
consumption.
Simple main injection:
Needle lift of fuel injector nozzle and pressure curve in
the cylinder without pilot injection
Combustion pressure in the cylinder1
Needle lift2
TDC (Top Dead Center)3
Needle lift for simple main injection4
Crank angle5
In the case of diesel engines with a distributor-type
fuel injection pump (for example in the Transit 2000.5),
the fuel injection on the pump-side is 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 steep pressure rise intensifies the combustion noise.
19Service Training (G544950)
Lesson 1 – General Information
Pilot injection
Needle lift of fuel injector nozzle and pressure curve in
the cylinder with pilot injection
Combustion pressure in the cylinder1
Needle lift2
TDC3
Needle lift for pilot injection4
Needle lift for main injection5
Crank angle6
In the case of vehicles with common rail injection
systems electrically-controlled pilot injection occurs
after a set time prior to the main injection event.
In the case of pilot injection, a small amount of fuel is
injected into the cylinder prior to the main injection.
Pilot injection results in a gradual increase in the
combustion pressure, leading to an improvement in
combustion quality.
The small, pilot injection fuel quantity is ignited and
heats up the upper part of the cylinder, thereby bringing
it into an optimum temperature range (pre-conditioning

of the combustion chamber).
This means that the main injection mixture ignites more
quickly and the rise in temperature is less abrupt as a
result.
This also results in a less abrupt increase in combustion
pressure, significantly reducing combustion noise.
Advantage:
• Continuous build-up of combustion pressure,
resulting in reduced combustion noise,
• Reduction of nitrogen oxides in the exhaust gas.
Note:As pressure generation and injection in common
rail systems are separate, it is possible to considerably
enhance the range for pilot injection (up to approx. 3000
rpm regardless of engine load). This has led to a decisive
improvement in the running characteristics of the engine.
Post-injection (vehicles with diesel particulate
filter system)
Needle lift of injector nozzle with pre- and post-injection
Needle lift1
Pilot injection2
Crank angle3
Main injection4
Advanced post-injection5
Retarded post-injection6
For vehicles with a diesel particulate filter system two
post-injections are employed during the regeneration
process, in addition to the pre- and main injections,
depending on the requirements.
(G544950) Service Training20
Lesson 1 – General Information

Advanced post-injection is initiated in certain
load/speed ranges immediately after main injection.
Fuel is then injected during the ongoing combustion.
The main purpose of this advanced post-injection is to
raise the exhaust gas temperature during the regeneration
process of the particulate filter. In addition, some of the
diesel particulates produced during regeneration are
after-burned.
Retarded post-injection only occurs shortly before
BDC (Bottom Dead Center) and also serves to raise the
exhaust gas temperature.
In contrast to the previous injections, during retarded
post-injection the fuel is not burnt, but evaporates 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 vapor 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 particulate filter.
Emission Standard IV with or without
diesel particulate filter
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 limit values are met.

Measures for the reduction of exhaust emissions inside
the engine include, for example:
• further optimized exhaust gas recirculation by means
of an electrically controlled EGR system with intake
air restriction,
• optimization of the combustion chamber design and
the injection characteristics.
In addition to optimization through internal engine
measures, the second method employs a diesel
particulate filter system.
With the use of diesel particulate filters, diesel
particulate emissions are reduced by more than 99%.
This reduction far exceeds the requirements for the
European emission limits of emission standard IV.
It can therefore be assumed that the use of the diesel
particulate filter 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.
21Service Training (G544950)
Lesson 1 – General Information
General
The EOBD system does not use any additional sensors

or actuators to individually measure pollutants in the
exhaust emissions.
The EOBD system is integrated into the software of the
PCM and uses the existing sensors and actuators of the
engine management system.
With the aid of these sensors, actuators and the special
software, systems and components significant for
emissions are continually checked during the journey
and exhaust emissions calculated accordingly.
Components significant for emissions are checked with
the so-called monitoring system.
With the introduction of EOBD for European Ford diesel
engines as of 1 January 2004 this will comprise the
following monitoring systems (monitors):
• monitoring of components significant to emissions
(Comprehensive Component Monitors = CCM),
• monitoring of the EGR system,
• boost pressure monitoring,
• fuel pressure monitoring.
Monitoring system for components significant
for exhaust emissions (CCM)
The monitoring system for components significant for
emissions (CCM) continually checks to see if the sensors
and actuators significant for emissions are operating
within the specified tolerances when the engine is
running.
If a sensor or actuator is outside the tolerance range,
this is recognized by the monitoring system and a DTC
is stored in the data memory.
Monitoring of the EGR system

The operation of the EGR system is monitored to
identify faults that lead to increased exhaust emissions
and may exceed the EOBD threshold values.
This monitoring system was developed so that it can,
among other things, check the flow characteristics of
the EGR system.
Boost pressure monitoring
Boost pressure control operates via the boost pressure
control solenoid valve and the MAP (Manifold Absolute
Pressure) sensor in a closed control loop.
The boost pressure is constantly monitored via the MAP
sensor.
Fuel pressure monitoring
Fuel pressure monitoring operates via the fuel metering
valve and the fuel pressure control valve. Feedback
regarding the current fuel pressure is received via the
fuel pressure sensor.
(G544950) Service Training22
Lesson 1 – General InformationEOBD
MIL (Malfunction Indicator Lamp)
The MIL is located in the instrument cluster and shows
an engine icon (international standard).
The MIL warns the driver that the EOBD system has
detected an emissions-related fault in a component or
system.
If an emissions-related fault is detected and if this fault
is confirmed during the third driving cycle, the MIL
is switched on.
After the MIL has been switched on, a fault log is
created in the PCM. The fault logs contain information

regarding the type of fault and the time since the MIL
was activated.
The MIL ensures that a fault is recognized in time. The
defect can be repaired in good time and the emission of
exhaust gas with high levels of pollutants is avoided.
Fault logging and storing
A fault occurring for the first time is labeled in the freeze
frame data as a suspected fault (pending code) and is
stored in the data memory.
If the fault is not confirmed in the next check, it is
erased.
If it is confirmed during the third drive cycle, the
suspected fault is automatically converted into a
confirmed fault (continuous code). The freeze frame
data does not change. It remains the same as when the
fault first occurred.
The MIL only illuminates when the fault has been stored
as a confirmed fault.
If the fault does not recur in the course of three
consecutive drive cycles, the MIL extinguishes in the
fourth drive cycle. However, the fault code remains
stored in the data memory.
Faults which do not reoccur are automatically cleared
from the memory after 40 warm-up cycles.
If a faulty signal is detected during a journey and the
corresponding fault code is stored, all the checks in
which this signal is required as a comparison variable
are interrupted. This prevents follow-up faults from
being stored.
Diagnostic trouble codes can be read or cleared with

the WDS ( Worldwide Diagnostic System) Ford
diagnostic tester.
Drive cycle
A drive cycle commences when the engine starts (engine
cold or hot) and ends when the engine is stopped.
Depending on the complexity of the fault, the
monitoring period may vary:
• For simple electrical faults, a monitoring period of
less than five minutes is sufficient.
• For the purpose of monitoring a system (for example
the EGR system) where different operating
conditions etc. are required to complete the test, the
test can take up to about 20 minutes.
23Service Training (G544950)
EOBDLesson 1 – General Information