FOX 2004 ➤
3 - Cyl. injection engine - Edition 12.2009
3
Engine power electronic adjustment
(electronic accelerator)
Operation ⇒ page 83 .
Engine power electronic adjustment (electronic accelerator)
⇒ page 84 .
3.1
Operation
The butterfly valve is not activated by a cable in the electronic
accelerator. There is no mechanical connection between the ac‐
celerator and the butterfly valve.
The position of the accelerator is transmitted to the Engine control
unit -J623- by two accelerator position sensors (variable resist‐
ance; stored in a case), which are connected to the accelerator.
The accelerator position (at the driver's criterion) is the main input
value for the Engine control unit -J623- .
The butterfly valve is activated by an electric engine (butterfly el‐
lk
ement) incorporated to the Throttle butterfly valve command unit
- J338- , in all load and rotation intervals.
The butterfly valve is activated by a butterfly element, due to the
data provided by the Engine control unit -J623- .
With the engine turned off and the ignition connected, the Engine
control unit -J623- activates the butterfly element, due to the data
provided by the Accelerator pedal position sensor -G79- . This
means that if the accelerator is half activated, the butterfly ele‐
ment will open proportionally, that is, the butterfly valve will be half
opened.
With the engine running (loaded), the Engine control unit -J623-
may open or close the butterfly, regardless of the Accelerator
pedal position sensor - G79- .
This way, the butterfly valve may, for instance, be completely
open already, even if the accelerator is only half activated. The
advantage is avoiding losses for chocking, caused by the butterfly
valve.
Also, this enables lower pollutant consumption and emissions for
certain load conditions.
The necessary torque may be obtained by the Engine control unit
-J623- , through an optimum combination between the butterfly
valve opening and the over-supply pressure.
Believing that the “electronic accelerator” comprises only one or
two components would be a mistake. The electronic accelerator
is a system comprised of all the components that contribute to
determine the position of the butterfly valve, in order to adjust it
and activate it, such as for example, Accelerator pedal position
sensor -G79- , Throttle butterfly valve command unit -J338- , "E-
gas" system fault warning light -K132- , Engine control unit -
J623- , etc).
3. Engine power electronic adjustment (electronic accelerator)
83
English 
