Individual Injector Calibration (C2I) - SSANGYONG 2004 Rexton 2.7XDi Workshop Manual

DI08-19

INDIVIDUAL INJECTOR CALIBRATION (C2I)

Injected fuel is proportional to square root of injection time and rail pressure.
It is function between pulse and rail pressure and fuel injection curve is called injector characteristics curve having the
following shape.
Drive pulse (µsec)
Y220_08012
Common rail injectors are very accurate components. They are able to inject fuel delivery between 0.5 to 100 mg/str
under pressure varying from 150 to 1600 bar.
This high level of accuracy requires very low machining tolerances (few ).
Nevertheless, due to the machining dispersion, the loss of charge through the functional orifices, the friction between
moving parts and electromagnetic field level are different from one injector to the other. So, the difference of fuel delivery
for the same pressure and the same pulse can reach 5 mg/str from one injector to the other. It is impossible to control
efficiently the engine with such a dispersion between the different injectors. It is necessary to add a correction that
allows injecting the demanded fuel delivery whatever the initial hydraulic characteristics of the injector is. The method
consists in correcting the pulse that is applied to the injector with an offset that depends on the initial hydraulic map of
the injector. So, the pulse should be corrected according to characteristics of each injector.
ENGINE CONTROL SYSTEM
CHANGED BY
DI ENG SM - 2004.4 EFFECTIVE DATE
AFFECTED VIN