Sensors and actuators for diesel engine power supply (Audi A6 C5)

The accelerator pedal position sensor is located on the pedal axis. The sensor potentiometer transmits information about the pedal position to the engine control unit. The gas cable is missing in this case. For this reason, such a gas pedal is called an "electronic accelerator" (see illustration 1.0a).

The mass air flow sensor with integrated intake air temperature sensor measures the volume of intake air.

Using the injector needle lift sensor, which is installed on one of the injectors, the actual start of fuel injection is monitored and fuel injection is performed with an advance or delay depending on the engine load at a specific moment.

Using a pulse sensor, the crankshaft rotation speed and, accordingly, the engine speed are recorded.

The exhaust gas recirculation valve directs a certain amount of exhaust gases for afterburning, depending on the engine load, mixing them with the intake air. This leads to a decrease in the combustion temperature of the air-fuel mixture. The lower the combustion temperature, the lower the content of toxic nitrogen oxides in the exhaust gases.

The brake pedal switch, together with the brake light switch, provides a reduction in the cyclic fuel supply to bring the engine to idle speed when the accelerator pedal sensor is disconnected and the driver brakes.

Due to the good cold starting properties of direct injection diesel engines, preheating is only necessary at temperatures below approximately -10°C. The glow plugs are activated by the microprocessor during preheating.