Engine Iveco C10/C13/C78/Cursor 13/Cursor 78. Manual — part 55
Figure 105
Air temperature transmitter on manifold
Specifications
Supplier
BOSCH
Max. tightening torque
35 Nm
The device should be marked with the supplier’s identification, catalogue number and date of manufacture.
TECHNICAL VIEW
8531
WIRING DIAGRAM
PERSPECTIVE VIEW
8530
RESISTANCE TREND
8532
8533
42
SECTION 3 - INDUSTRIAL APPLICATION
Pin
Function
Cable colour
1
To pin 21 of EDC control unit
–
2
To pin 4 of EDC control unit
–
PRE/POST-HEATING RESISTANCE
The resistance is ~ 0,7 Ohm.
Such resistance is placed between the cylinder head and the suction manifold. It is used to heat up air during pre/post-heating
operations.
When the ignition key is inserted, should any one of the temperature sensors — water, air, gas oil — detect a value below 10
°C,
the electronic control unit will activate pre/post-heating and turn on the relevant dashboard warning light for a variable time
depending on the temperature.
After that time, the warning light starts blinking thus informing the driver that the engine can be started.
When the engine is running the warning light goes off, while the resistance is being fed for a certain time as a result of post-heating.
If the engine is not started, with the warning light flashing, in 20 / 25 seconds, the operation is cancelled to prevent draining the
battery.
On the contrary, if reference temperatures are over 10
°C, when the ignition key is inserted the warning light comes on for about
2 seconds and carries out the test and then goes out to signal that the engine can be started.
Figure 106
001256t
SECTION 3 - INDUSTRIAL APPLICATION
43
EDC SYSTEM FUNCTIONS
The MS6.2 electronic center manages the following main functions:
Fuel injection
Accessory functions
Self-diagnosis
Recovery
It also enables:
Interfacing with other electronic systems (if any) available on the vehicle
Diagnosis
Fuel dosing
Fuel dosing is calculated based on:
-
accelerator pedal position
-
engine rpm
-
quantity of air admitted.
The result can be corrected based on:
-
water temperature
or to prevent:
-
noise
-
fumes
-
overloads
-
overheating
Pressure can be adjusted in case of:
-
engine brake actuation
-
external device actuation
-
serious defects involving load reduction or engine stop.
After determining the mass of air introduced by measuring its volume and temperature, the center calculates the corresponding
mass of fuel to be injected into the cylinder involved, with account also taken of gas oil temperature.
Delivery correction based on water temperature
When cold, the engine encounters greater operating resistance, mechanical friction is high, oil is till very viscous and operating plays
are not optimized yet.
Fuel injected also tends to condense on cold metal surfaces.
Fuel dosing with a cold engine is therefore greater than when hot.
Delivery correction to prevent noise, fumes or overloads
Behaviors that could lead to the defects under review are well known, so the designer has added specific instructions to the center
to prevent them.
De-rating
In the event of engine overheating, decreasing delivery proportionally to the temperature reached by the coolant changes injection.
44
SECTION 3 - INDUSTRIAL APPLICATION
Injection lead electronic control
Injection lead, or the start of fuel delivery expressed in degrees, can differ from one injection to the next, even from one cylinder
to another and is calculated similarly to delivery according to engine load.
Lead is corrected as required:
-
during acceleration
-
according to water temperature
and to obtain:
-
reduced emissions, noise abatement and no overload
-
better vehicle acceleration
High injection lead is set at start, based on water temperature.
Delivery start feedback is given by injection electro valve impedance variation.
Engine start
Cylinder 1 step and recognition signal synchronization (flywheel and drive shaft sensors) takes place at first engine turns. Accelerator
pedal signal is ignored at start. Star delivery is set exclusively based on water temperature, via a specific map. The center enables
the accelerator pedal, when it detects flywheel acceleration and rpm such as to consider the engine as started and no longer drawn
by the starter motor.
Cold start
Pre-post reheating is activated when even only one of the three water, air or gas oil temperature sensors records a temperature
of below 10 _C. The pre-heat warning light goes on when the ignition key is inserted and stays on for a variable period of time
according to temperature, while the intake duct input resistor heats the air, then starts blinking, at which point the engine can be
started.
The warning light switches off with the engine revving, while the resistor continues being fed for a variable period of time to
complete post-heating. The operation is cancelled to avoid uselessly discharging the batteries if the engine is not started within 20
÷ 25 seconds with the warning light blinking. The pre-heat curve is also variable based on battery voltage.
Hot start
On inserting the ignition key the warning light goes on for some 2 seconds for a short test and then switches off when all reference
temperatures are above 10 _C. The engine can be started at this point.
Run Up
When the ignition key is inserted, the center transfers data stored at previous engine stop to the main memory (Cf. After run),
and diagnoses the system.
After Run
At each engine stop with the ignition key, the center still remains fed by the main relay for a few seconds, to enable the
microprocessor to transfer some data from the main volatile memory to an non-volatile, cancelable and rewritable (Eeprom)
memory to make tem available for the next start (Cf. Run Up).
These data essentially consists of:
-
miscellaneous settings, such as engine idling and the like
-
settings of some components
-
breakdown memory
The process lasts for some seconds, typically from 2 to 7 according to the amount of data to be stored, after which the ECU sends
a command to the main relay and makes it disconnect from the battery.
SECTION 3 - INDUSTRIAL APPLICATION
45
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст