Iveco daily euro 4, Repair Manual

Page: 323 / 1132

SYSTEM OPERATION
Self-diagnosis — BLINK CODE
The control unit self-diagnosis system checks the signals from
the sensors, comparing them with the admitted limits (see
relative heading):
Immobilizer recognition
When the control unit receives the signal of the key on ”MAR”
it communicates with the immobilizer control unit to enable
starting.
Checking fuel temperature
With the fuel temperature greater than 75
°
C, detected by the
sensor on the fuel filter, the control unit operates the pressure
regulator to decrease the line pressure (injection times are not
changed). If the temperature exceeds 90
°
C, the power is
reduced to 60%.
Checking engine coolant temperature
The control unit, depending on the temperature:
- of the engine coolant, turbocharging air and fuel, operates
the electromagnetic fan (Baruffaldi) and switches on the
coolant temperature warning light.
Checking quantity of fuel injected
According to the signals from the sensors and the mapped
values, the control unit:
- operates the pressure regulator;
- varies the ”pilot” injection time to 2200 rpm;
- varies the ”main” injection time.
Checking idling adjustment
The control unit processes the signals from the various sensors
and regulates the amount of fuel injected:
- it operates the pressure regulator;
- it varies the injection times of the electro-injectors.
Within certain thresholds the speed takes account of the
battery voltage.
Fuel cut-off in release phase
In the phase of releasing the throttle pedal the control unit
actuates the following logic elements:
- it cuts off supply to the electro-injectors;
- it partially reactivates supply to the electro-injectors before
reaching idling speed;
- it operates the fuel pressure regulator.
Checking cylinder balancing on idling
According to the signals received from the sensors, the control
unit controls the regularity of the torque at idling speed:
- it varies the amount of fuel injected into the single
electro-injectors (injection time).
Checking regular engine rotation (anti-sawing)
It ensures regular engine rotation at a constant rate while
increasing revs.
The control unit processes the signals received from the
sensors and determines the amount of fuel to be injected via:
- the pressure regulator;
- the electro-injector opening time.
Checking smokiness at exhaust on
acceleration
With heavy acceleration, on the basis of the signals received
from the air introduction meter and engine speed sensor, the
control unit determines the optimum amount of fuel to inject:
- it operates the pressure regulator;
- it varies the electro-injector injection time.
Checking exhaust gas recirculation (E.G.R.)
Depending on the engine load and the signal from the
accelerator pedal sensor, the control unit limits the amount of
air taken in, actuating partial suction of the exhaust gases.
Checking top speed limit
Depending on the number of revs, the control unit actuates
two action strategies:
- at 4250 rpm it cuts off the fuel, decreasing the
electro-injector opening time;
- over 5000 rpm it deactivates the electro-injectors.
Checking regular rotation on acceleration
Regular progression is assured in all conditions by the control
of the pressure regulator and the electro-injector opening
time.
Checking glow plug control unit
The injection control unit, in the phase of:
- starting
- after-starting
times operation of the glow plugs according to the engine
temperature.
Checking activation of air-conditioning system
The control unit operates the air-conditioning compressor:
- switching it on/off when the relative switch is pressed;
- momentarily turning it off (approximately 6 sec.) if the
engine coolant reaches the set temperature.
Checking fuel pump
Irrespective of the speed, the control unit:
- supplies the auxiliary fuel pump with the key on MAR;
- cuts off auxiliary pump supply if the engine is not started up
within a few seconds.
F1C ENGINE
295
D
AILY
E
URO
4
Print 603.93.651 Base - March 2006
Print 603.93.281