SYSTEM
ECK-33
< SYSTEM DESCRIPTION >
[K9K]
C
D
E
F
G
H
I
J
K
L
M
A
ECK
N
P
O
The high-pressure pump is self-supplied by an integrated gear pump. This supplies the rail, whose pressure is
controlled for loading by the fuel flow actuator. The flow regulation actuator allows the high-pressure fuel pump
to supply only the necessary quantity of diesel for maintaining pressure in the rail.
INJECTION CONTROL
The injection control parameters are the quantities to inject and their respective advances. The system per-
forms one to six injections.
An electrical current (impulse or pulse) is sent to each injector holder based on the previously computed data.
The piezoelectric injectors ensure injected fuel quantity with an excellent repeatability of the injection process.
Piezoelectric actuators work like capacitors. To control the injector, ECM punctually drives energy resulting in
the actuator deformation and injector opening.
During the injection time, piezoelectric actuator stores this energy, the length of electrical pulse is computed
with the fuel flow demand and injectors characteristics. At the end of the injection time, ECM recovers energy
to send at the start of control. Piezoelectric actuator then discharges and returns to its initial shape. The injec-
tor nozzle closes.
Injector Adjustment Value Registration
At the factory, each injector is calibrated for specific pressure needs on a test bench, and the values are indi-
cated on a label attached to the injector holder body. The individual injector correction values are then written
to ECM, enabling the ECM to control the injectors by taking into account the variance from the factory produc-
tion dispersion.
A specific strategy controls fuel injection deviations and dispersion during engine life (called Minimum Fuel
Mass Adaptation strategy).
This function defines individual injector correction to compensate the injector drift to enhance the delivery fuel
accuracy.
TEMPERATURE BEFORE TURBINE CONTROL
Upstream turbine temperature control sequentially uses injection parameters:
• Main injection phasing
• Post injection fuel mass
• Total fuel mass quantity
• Maximum torque
In normal combustion mode (without regeneration), the regulation aims to protect the turbine. when the tem-
perature exceeds the recommended limits, the regulation is able to limit total fuel mass quantity and torque
demand.
In regeneration mode, to increase the temperature in exhaust line, the regulation controls main injection phas-
ing and post injection.
The purpose is to obtain the highest temperature while respecting the recommended limits. In addition, the
regulation protects the turbine when the temperature is too hot.
WATER IN FUEL FUNCTION
The water in fuel detection sensor is an optional sensor integrated in the fuel filter. This function prevents seri-
ous damages on the common-rail system caused by water presence.
AFTER TREATMENT SYSTEM
AFTER TREATMENT SYSTEM : System Description
INFOID:0000000010471227
DESCRIPTION
This system has two main functions:
• Use the present oxygen in exhaust gases to transform the CO in CO2, and the HC in CO2 and H2O.
• Increase the temperature of exhaust gases (with the exothermal energy of the oxidation reaction) to allow
the regeneration in the DPF (Diesel Particulate Filter).
To be effective, the catalytic converter must reach the working temperature of 350 to 400
°
C (662 to 752
°
F).
DPF (DIESEL PARTICULATE FILTER)
The DPF filters up to 99% of the soot particulates that have not been filtered out up to this point. These partic-
ulates consist essentially of micro-spherules of carbon on which hydrocarbons from the fuel and lubricant
have condensed.
The quantity of particulates and their composition depend on:
• The combustion process (an homogeneous air/fuel mixture minimizes particulate formation)
• The quantity of diesel (increasing the cetane index limits the number of particulates formed)
• The post-processing efficiency (only filtration allows the particulates to be removed efficiently)