Camshaft position sensor in diesel engine: the core of precise control

Basic knowledge of camshaft position sensor
As part of the engine management system, the camshaft position sensor is mainly responsible for monitoring the rotational position and speed of the camshaft. This information is crucial for the engine because it is directly related to the opening and closing timing of the valve, which in turn affects key processes such as fuel injection, ignition (for gasoline engines) and exhaust. In diesel engines, although there is no ignition system, the role of camshaft position sensor is still indispensable, which is directly related to the precise control of fuel injection.

Unique fuel injection technology of diesel engine
Compared with gasoline engines, the biggest feature of diesel engines is its fuel injection method. Diesel engines generally use high-pressure common rail system or single pump technology, which can achieve extremely high fuel injection pressure (usually more than 1000 bar), thereby ensuring that the fuel is sprayed into the cylinder in a very fine mist, greatly improving combustion efficiency and power output. The high-pressure common rail system pressurizes the fuel through a high-pressure oil pump and stores it in the common rail. The electronic control unit (ECU) accurately controls the opening timing and duration of each injector according to the signal provided by the camshaft position sensor to achieve on-demand injection. The single pump system is equipped with an independent high-pressure pump for each cylinder, and also relies on the precise feedback of the camshaft position sensor to achieve synchronous control.

The role of camshaft position sensor in diesel engine
Fuel injection control: The precise position information provided by the camshaft position sensor enables the ECU to accurately calculate when to start the injector and the duration of each injection, thereby optimizing the fuel-air mixture ratio and ensuring the best combustion effect. This is essential for reducing emissions, improving fuel economy and engine power.
Engine start and idle speed control: During the startup phase, the camshaft position sensor helps the ECU identify the first turn of the engine, so as to start fuel injection and ignition in time (for some diesel engines equipped with preheating plugs) to ensure smooth start. When idling, the sensor continuously monitors the camshaft position, adjusts the fuel injection amount, and maintains a stable engine speed.
Protection function: The camshaft position sensor can also monitor abnormal conditions in engine operation, such as camshaft damage or misalignment, and promptly warn the ECU to prevent the engine from being damaged due to improper operation. This function is of great significance to ensure the long-term stable operation of the engine.