Electronic Power Control System Function

Electronic Power Control System Function

For EPC, the throttle valve is not operated by a cable from the accelerator pedal. There is no mechanical connection between the gas pedal and the throttle valve.

The position of the accelerator pedal is transmitted to the ECM via two accelerator pedal position sensors (adjustable resistances, accommodated in one housing), that are connected to the accelerator pedal.

The position of the accelerator pedal (driver controlled) is a main input for the ECM.

Operation of the throttle valve occurs via an electric motor (throttle valve actuator) in the throttle valve control module. This applies across the entire engine speed and engine load spectrum.

The throttle valve is operated by the throttle valve actuator as instructed by the ECM.

With the engine stopped and the ignition switched on, the ECM activates the throttle valve actuator according to the specifications from the throttle position sensor. This means, if the accelerator pedal is depressed half way, the throttle drive opens the throttle valve to the same degree; i.e. throttle valve is then opened approximately half way.

With engine running (under load) the ECM can open and close the throttle valve independently of the accelerator pedal position sender.

That way e.g. the throttle valve can already be completely opened, although the accelerator pedal is only depressed half-way. This has the advantage of preventing torque losses at the throttle valve.

The ECM calculates after evaluation of torque requirements of the different components (e.g. A/C system, automatic transmission, ABS/ESP, etc.) a throttle valve opening angle optimal for the respective situation.

Aside from that, it results in clearly better pollutant output and consumption values under certain load conditions.

"E-Gas" is a system that encompasses all components that regulate and supervise the throttle valve, e.g., the accelerator pedal position sender accelerator pedal position sensor, the throttle valve control module, the EPC warning light, and the ECM.