Iveco Daily. Manual

The quantity injected by each injector in each cycle is
therefore:

where

injected quantity in mm

/cycle/cylinder

hourly consumption in kg/h

speed in rpm

fuel density in kg/dm

(

diesel oil

= 0.835 kg/dm

while

with

number of cylinders

number of strokes (2 or 4)

It may immediately be seen how in the case of the test bench
the delivery is measured for each single injector, whereas with
the engine on the bench the delivery is averaged over the
number of injectors. In this last case, it is therefore not known
whether there are differences between the injectors. It is
therefore useful to measure the temperature of the exhaust
gas of each cylinder, a fairly reliable index of the torque
delivered by each single cylinder and therefore of the amount
of fuel introduced with each cycle. On the basis of these
measurements it is possible to tell whether the injectors have
a similar behaviour to one another.
To do this it is necessary to have thermocouples or
thermometers to be placed in contact with each exhaust
manifold outlet, in the area close to the cylinder head fixing
flange.

Figure 256

= C

⋅ 1

60 ⋅

eNG ⋅

8 ⋅ 10

⋅ 2

ELECTRIC/ELECTRONIC COMPONENTS
766161

Electronic control unit MS6.3 or
EDC 16

The control unit is a ”flash EPROM” and so it can be
reprogrammed from outside without changing the hardware.
The injection control unit has the absolute pressure sensor
built in to further improve the control of the injection system.
The control unit is mounted on the left-hand side of the engine
bay and is connected to the vehicle’s wiring harness by two
connectors:

MS6.3:

—

43-pin connector A for the components on the engine

—

43-pin connector B for the components on the vehicle

90638

EDC.16:

—

60-pin connector A for the components on the engine

—

94-pin connector K for the components on the vehicle

In addition to handling the operation of the system described
under the relevant heading, the electronic control unit is
interfaced with the other electronic systems on the vehicles
such as ABS - ABD - EBD cruise control, speed limiting device,
immobilizer (IVECO CODE).

SENSORS

Engine speed sensor

This is an inductive sensor and is positioned on the flywheel.
It generates signals obtained from lines of magnetic flux that
close through holes in the flywheel. There are 58 holes.
The electronic control unit uses this signal to measure the
speed of rotation of the engine, its angular position and to
operate the electronic rev counter.
If this signal fails the rev counter will not work.

Camshaft timing sensor

It is either an inductive type sensor for MS6.3 central unit or
a Hall effect type sensor for EDC.16 central unit, and it is
positioned on timing system shaft pulley.
The signal generated by this sensor is used by the electronic
control unit as a redundant signal to measure the different
engine speeds.

772655

Air temperature and pressure sensor

Positioned on the intake manifold, it measures the pressure of
the turbocharging air introduced into the intake manifold.
This value, together with that of the air temperature sensor,
makes it possible for the electronic control unit to calculate the
exact quantity of air introduced into the cylinders so as to
operate the injectors adjusting the fuel delivery, limiting
harmful emissions, improving consumption and performance.
The sensor contains an electronic temperature correction
circuit to optimize the pressure measurement in relation to the
temperature of the intake air.

772656

Fuel temperature sensor

Integrated in the fuel filter, it measures the fuel temperature
and transmits it to the electronic control unit.
When the fuel temperature is too high (ambient temperature,
engine at full load and tank in reserve), correct lubrication of
the high-pressure pump is no longer assured. On the basis of
the values received, the control unit determines the density
and volume of the fuel, correcting the delivery limiting engine
performance.

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ACTUATORS

The injection system comprises three classes of actuators
interlocked with the electronic control unit:

- electro-injectors (see relevant heading);

- regulators (see relevant headings) requiring PWM control

(Pulse Width Modulation):
•

for pressure

•

EGR (if mounted)

•

turbocharger with variable geometry (if mounted);

- actuators with continuous ON/OFF signal to:

•

engage electromagnetic coupling for radiator cooling
fan;

•

turn on/off air-conditioner compressor (if mounted);

•

Cruise Control;

•

thermostart control;

•

fuel filter heating;

•

electric supply pump.

PWM (Pulse Width Modulation) controls

A PWM control has an active and an inactive state that
alternate within a constant set length of time. During the active
state the actuator control circuit is closed, which is thus
powered with the control voltage; whereas, during the
inactive state the circuit is open.
The duration of the two states may be varied with the
condition that the sum of the two times is equal to the length
of the modulation delivery.
The duration of the active state determines the duty-cycle,
which is normally expressed as a percentage of the total time.
Therefore, if the duration of the two active and passive states
are the same, the duty-cycle is equal to 50%.
For reasons of diagnostics, the duty-cycle is limited between
1% and 99%; the control resolution is equal to 0.005%
(1/20000 of the time).
The time length has been chosen taking account of the
dynamic actuator response specifications.
Too low a carrier frequency could cause oscillations in the
actuator, while too high a frequency would decrease control
resolution.
The E.G.R. and variable geometry turbocharger (if mounted)
are controlled through a vacuum modulating valve.

774511

Fuel pressure sensor

This is mounted in the middle of the hydraulic accumulator
(rail) and it has the task of providing feedback for the injection
control unit to:

—

adjust injection pressure

—

adjust the duration of injection.

766161

Atmospheric pressure sensor

This is integrated in the electronic control unit. It provides a
criterion of correction for the measurement of the air flow
rate and to calculate the reference air flow rate to check the
EGR.

764254

Engine coolant temperature sensor

This provides the control unit with an index of the thermal
status of the engine in order to determine corrections for the
fuel delivery, injection pressure, EGR injection advance when
starting cold (if mounted) and Warm-Up.

505910

Throttle pedal position sensor

The accelerator pedal position sensor provides the control
unit with a voltage value in proportion to the angle of
operation of the pedal determining fuel delivery.

772641

Clutch pedal position sensor

Mounted on the pedal board, it provides the control unit with
a positive signal when the clutch is engaged (pedal released).
Every time the clutch is disengaged to change gear, the control
unit fails to receive this signal and deactivates the Cruise
Control function.

772642

Brake pedal position sensor

There are two of these sensors mounted on the pedal board.
With the brake pedal released, they provide the control unit
with a positive signal that is used to detect brake operation so
as to deactivate the Cruise Control function and stop delivery
of fuel.
In addition, a sensor switches on the brake lights.

764261

Vehicle speed sensor

This sensor, mounted on the gearbox by the drive output
shaft, transmits the vehicle speed signal, through the electronic
tachograph, to the control unit.

All the power controls are made with relays located
in the cab.

NOTE

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EXHAUST GAS RECIRCULATION SYSTEM
E.G.R.
(vehicles with homologation MI)

The EGR system is similar to the one made on the 8140.63
engine and covered under the specific heading.

It differs from the version on 8140.63 engines in the control
performed by the EDC control unit and in the different
settings of the modulating solenoid valve and of the pneumatic
one of the EGR.

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INTRODUCTION

Good diagnostic is mainly obtained when using Iveco electronic diagnostic tools (Modus/IWT).

When a vehicle enters the workshop, information given by the driver shall be taken in duly consideration but the first thing to
do is to connect Modus/IWT and to perform an accurate and thorough diagnostic analysis:

failure memory reading;

parameter reading;

engine test;

etc.

Another factor that favours failure solving is experience.
To remove in part the lacking of experience of repair operators on this new electronic system, (since there is no previous system
to be used for reference), the following pages contain a GUIDE TO TROUBLESHOOTING drawn up by Training together with
the experts that have designed and developed Common Rail MS6.3 or EDC 16.

Take into account that ”Troubleshooting” cannot replace Modus/IWT, but it is a further aid, a sort of condensed experience
derived from the in-depth knowledge of the system.

”Troubleshooting” is divided into two separate sections:

the first one, organised according to Blink Codes or DTC-FMI, concerns failures that can be directly detected by MS6.3 EDC
16. These failures are mainly electric - electronic;

the second one, organised according to symptoms, describes failures that cannot be directly detected by the ECU. These
failures are mainly mechanical - hydraulic.

”Troubleshooting” does not replace diagnostic through Iveco electronic diagnostic tools but is an integration to it.

Content .. 34 35 36 37 ..

Iveco Daily. Manual - part 36