Electronic accelerator pedal (Audi A4 B6)

The Audi A4 models are equipped with an electronic accelerator pedal. The throttle valve is no longer actuated via a cable. There is no mechanical connection between the two parts. Instead, there are two sensors on the accelerator pedal (variable resistances in the case), which inform the control device about the position of the accelerator pedal.



The accelerator pedal position, determined by the driver, is the main input value for the control unit. The throttle valve is driven by an electric motor (throttle position controller), which is located in the throttle control device. Control is performed in the entire range of loads and rotation speeds. The valve is driven by the regulator in accordance with the signal from the setter, which is the engine control device.





When the engine is not running and the ignition is on, the electronic circuits of the control unit control the position of the throttle valve in precise accordance with the signals from the accelerator pedal position sensor. In this case, if the accelerator pedal is pressed halfway, the throttle valve also opens approximately halfway. On the other hand, when the engine is running, i.e. under load, the control unit can open and close the throttle valve independently of the throttle position sensor. In this way, adaptation to the corresponding operating mode is carried out. Thus, when accelerating, the throttle valve can be fully open, although the accelerator pedal is pressed only halfway. This avoids throttle losses.

This enables significantly better values in terms of emissions and fuel consumption under certain load conditions. The control unit generates the corresponding torque by means of an optimum ratio of throttle cross-section and boost pressure.

The electronic accelerator pedal also intervenes in the process of regulating the traction of the drive wheels. If the driver accelerates too much, the control device can reduce the gas supply until all wheels stop slipping. With an electronic accelerator pedal, there is also no need for additional stabilization of the idle speed. The idle speed is adjusted automatically by means of the throttle valve. As you probably already guessed, it is impossible to repair the electronic accelerator pedal yourself without special diagnostic devices, because now we are not talking about some simple unit that consists of a couple of parts. The electronic engine power control system is a system that includes all the parts that help determine, adjust and control the position of the throttle valve.