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Fuel supply system -> 2 Electronic power control (EPC) for Your Volkswagen Touareg SUV First Generation (2002-2010)

lk  
Touareg 2003 ➤  
8-cylinder injection engine - Edition 11.2011  
2
Electronic power control (EPC)  
1 - Bearing bracket  
❑ Removing and instal‐  
ling: ⇒ Brake systems;  
Rep. gr. 46 ; Assembly  
overview - brake pedal  
(LHD) .  
2 - Connector  
❑ Black, 6-pin.  
3 - 10 Nm  
4 - Accelerator position sender  
-G79- and accelerator position  
sender 2 -G185-  
❑ Not adjustable.  
❑ Remove footwell cover  
to remove sender.  
Function of EPC system  
The position of the accelerator is transmitted to the engine control  
unit by two accelerator position senders (variable resistors to‐  
gether in one housing) connected to the accelerator.  
The position of the accelerator (driver's requirement) is a main  
input value for the engine control unit.  
The throttle valve is operated over the complete engine speed  
and load range by an electric motor (throttle valve positioner) in  
the throttle valve module.  
The throttle valve is operated by the throttle valve positioner which  
is controlled by the engine control unit.  
When the engine is not running and the ignition is switched on,  
the engine control unit moves the throttle valve exactly as pre‐  
scribed by the accelerator position sender. That is, 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.  
2. Electronic power control (EPC)  
115  
lk  
Touareg 2003 ➤  
8-cylinder injection engine - Edition 11.2011  
When the engine is running (under load), the engine control unit  
can open or close the throttle valve independently of the accel‐  
erator position sender.  
This means that the throttle valve can already be completely open  
even though the accelerator is only depressed half way. This has  
the advantage of preventing throttling losses at the throttle valve.  
This also results in significantly improved consumption and ex‐  
haust emission values under certain load conditions.  
The torque required by the engine can be produced by the engine  
control unit by optimising the combination of throttle valve cross-  
section and charge pressure.  
After evaluating the torque requirements of various components  
(e.g. air conditioning system, automatic gearbox, ABS/ESP and  
so on), the engine control unit calculates the optimal throttle valve  
opening angle for the respective situation.  
Observe safety precautions.  
Observe rules for cleanliness.  
116  
Rep. gr.20 - Fuel supply system