Electronic Power Control System

Electronic Power Control System

The position of the accelerator pedal is transmitted to the Engine Control Module (ECM) (J623) 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 is true across the entire engine speed and engine load spectrum.

The throttle valve is operated by the throttle drive according to the instructions of the ECM.

With the vehicle at a stand still and the ignition switched on, the ECM activates the throttle valve actuator precisely according to the specifications of the Throttle Position (TP) sensor. This means, if the accelerator pedal is pressed half way, the throttle drive opens the throttle valve to the same degree; i.e. 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.

That way e.g. 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.

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

According to torque requirement outputs from the various components (e.g. air conditioning, automatic transmission, Anti-lock Brake System/Electronic Stabilization Program (ABS/ESP)...), the ECM calculates a throttle valve open angle that is optimal for a respective situation.

Read the safety precautions before beginning work. Refer to => [ Safety Precautions ] Safety Precautions.

Observe rules for cleanliness. Refer to => [ Clean Working Conditions ] Fuel Supply.