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ENGINE 1.3 QUADRAJET (75PS)
Small Injection Control (SIC)
The SIC procedure is a function meant to optimize the ratio between the energizing time and fuel quantities in
particular for small quantities.As a consequence, this function optimize the exhaust emission, especially engine
noise level and roughness during the first Km (new engine)
To obtain such result it is necessary to check the exact quantity of fuel injected by each electric injector so as to
define not only the IMAprocedure but also the characteristics of each injector.
The control unit will st art recording the self adapt ability of each electric injector , then saving the dat a in its
permanent memory (Eprom memory), the function is enabled under CUT OFF conditions. By acting on the injec-
tion time and increasing the target value of each cylinder the system verifies whether there is significant angular
change in flywheel. If the variation in the flywheel is not detectable yhe injected quantity is increased at each cycle
under cut off conditions until a variation in the flywheel angular speed is detected.
Once the Flywheel correction is determined, such value will be used to calibrate the actual fuel quantity injected
by electro injector
Immobilizer system is designed to prevent vehicle theft by electronically disabling the engine starting system. The
engine can be started only with vehicle’s original immobilizer ignition key, which has an electronic identification
code.
SIC Procedure
To guarantee the correct functionality of the strategy, and therefore correct update of self adaptive parameters, the
system should always work under best stability conditions of both the components exerting the rail pressure
(pressure pump and adjuster, electro injectors) and the sensors that, by reading the p arameters, significantly
affect the adjustment of the injected quantities / pressures (rail pressures read by specific sensors)
So whenever one or more components, actively affecting the functionality of SIC strategy, are replaced, service
shall use diagnostic tool to perform series of procedures meant to zero some self adaptive parameters in the ECU
Eprom so that there values get back to default.
SIC strategy is divided into two functional parts –
SIC1
and
SIC2
The difference between two strategies is that SIC1 acts on the correction of injected quantity of all electro injectors
whereas SIC2 is specific to each single injector.
Whenever one of the following components are replaced it is necessary to perform SIC1/SIC2 procedure
•
ECU
•
One or more Injector
•
Rail pressure sensor
The table below defines the correlation between the replaced components and SIC1 & SIC2 procedures.
Replaced
SIC1 SIC2 Impacts
Components
ECU
X NO If during the replacement of one or more components defined here is on the
Single Injector
NO X side the describe procedure is not applied, the engine noise level could
All Injector
X NO increase however assuring the required emission limits
Rail Pressure
X NO
Sensor
