Electronic Power Control System

Electronic Power Control System

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 sensors. 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 a load) the ECM can open and close the throttle valve independently of the accelerator pedal position sensor.

That way, for example, the throttle valve can already be completely opened, although the accelerator pedal is only pressed half way. This has the advantage of preventing torque losses at the throttle valve.

The ECM recalculates after evaluation of the torque requirements of the different components (for example, Air Conditioning (A/C) system, automatic transmission, Anti-lock Brake System (ABS)/Electronic Stabilization Program (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, for example the accelerator pedal position sensors, the throttle valve control module, the EPC warning lamp, and the ECM.