Bentley Volkswagen.Golf.Jetta.R32.Official.Factory.Repair.Manual.1999-2005

Electronic Power Control (EPC)
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Electronic Power Control
(EPC)
Function of EPC systems
With the EPC system the throttle valve is not
operated by the throttle pedal via a cable.
There is no mechanical connection between
accelerator and throttle valve.
The position of the accelerator is transmitted
to the engine control module by two sensors
(variable resistors; mounted in one housing)
which are connected to the accelerator
pedal.
The position of the accelerator (drivers
requirement) is the main input value for the
engine control module.
An electric motor (throttle actuator) in the
Throttle valve control module -J338-
actuates the throttle valve over the entire
range of engine speeds and load.
The throttle valve is operated by the throttle
actuator under instructions from the engine
control module.
When the engine is not running and the
ignition is switched on the engine control
module moves the throttle valve exactly as
prescribed by the accelerator pedal position
sender. This means that when the
accelerator is depressed halfway the throttle
valve positioner opens the throttle valve by
the same amount, the throttle is then
approximately half open.
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12/2/2005