Accelerator Pedal Potentiometer - Alfa Romeo 159 Training Material

ENGINE
V
4,8
4,5
Tensione
segnale
0,5
0,2
FUNCTION: This sensor provides a feedback signal to the injection ECU to:
adjust pressure inside the fuel rail
adjust injection time.

Accelerator pedal potentiometer

LOCATION: The accelerator pedal potentiometer consists of an armature fastened to the accelerator pedal.
FUNCTION: It provides information to the engine ECU on the position of the accelerator pedal which is integral with
the potentiometer itself.
OPERATION: Mechanically, the potentiometer consists of an armature inside which a spindle turns (the spindle is
integral with the accelerator pedal). A helical spring ensures return to home position when the pedal is not pressed.
Two potentiometers are fitted inside the armature (one main potentiometer and one backup). Their resistance varies
according to the angle of rotation of the spindle (i.e. the angular position of the accelerator pedal) with which they are
integral.
The changes in resistance offered by the potentiometer is read by the ECU.
Two potentiometers are provided for safety reasons.
A coil spring on the shaft ensures the correct resistance to pressure of the pedal while a second spring ensure return
when the pedal is released.
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