Electronic Power Control System Function

Electronic Power Control System Function

For Electronic Power Control (EPC), the throttle valve is not operated by a cable from the accelerator pedal. There is no mechanical connection between the accelerator pedal and the throttle valve.

The position of the accelerator pedal is transmitted to the Engine Control Module (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 turned on, the ECM activates the throttle valve actuator according to the specifications from the accelerator pedal position sensor. This means, if the accelerator pedal is pressed half way, the throttle drive opens the throttle valve to the same degree; for example, the throttle valve is then opened approximately half way.

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

This means, for example, that the throttle valve could be fully opened even though the accelerator pedal has only been pressed half way. This has the advantage of preventing torque losses at the throttle valve.

After evaluating the torque requirements of the various components (such as the Air Conditioning (A/C) system, automatic transmission, Anti-lock Brake System (ABS)/Electronic Stabilization Program (ESP), etc.), the ECM calculates the optimal throttle valve opening angle for the current 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 the components that regulate and monitor the throttle valve, for example, the accelerator pedal position sensor , the throttle valve control module, the EPC warning lamp and the ECM.