The engine is composed of two major mechanisms (crank train mechanism, valve train mechanism) and five major systems (fuel supply system, cooling system, lubrication system, starting system and ignition system).

Sensors include diesel engine speed, accelerator pedal position, rack position, fuel injection time, vehicle speed and intake air pressure, intake air temperature, fuel temperature, cooling water temperature and other sensors.

The ECU communicates with the ECU based on the diesel engine operating parameters detected in real time by various sensors. It is compared with the parameter values or parameter maps (called MAP) that have been stored in advance, and the instructions are sent to the actuator according to its optimal value or calculated target value. The actuator controls the injection quantity (rack position or solenoid valve closing duration) and injection timing (timing control valve opening and closing or solenoid valve closing starting point) according to ECU instructions. The electronically controlled diesel injection system can also exchange data with the ECU of the vehicle's transmission device, the ECU of the anti-lock braking system ABS and other systems to achieve electronic control of the vehicle.

The cooling system includes water pump, radiator, expansion tank, cooling water pipe, coolant, thermostat, coolant temperature sensor, cooling fan, liquid level sensor, coolant temperature alarm light and coolant temperature gauge, etc.

(1) The coolant temperature sensor is used to monitor the current coolant temperature to determine whether the current engine heat dissipation is normal.

(2) The liquid level sensor monitors the amount of coolant in the expansion tank and prompts the driver whether it needs to be added.

The air intake system mainly includes the air filter assembly, turbocharger, intercooler, intake manifold, intake pipe assembly, air flow sensor and throttle assembly, etc.

(1) The air flow sensor converts the inhaled air flow into an electrical signal and sends it to the electronic control unit as one of the basic signals that determines the fuel injection time.