CRDI system includes Engine Control Unit, Fuel Injectors, High Pressure Pumps and various Sensors.

Pump driven by camshaft provides high pressure fuel to all injectors. This pressure level is controlled by ECU depending upon operating speed/power. Each injector has a solenoid valve to accurately control the fuel injection start and duration. ECU controls these parameters based on operating conditions like speed, power, load, Boost Air Pressure, Coolant Temperature etc. This continuous optimization based on various operating conditions is done to reduce fuel consumption and at the same time reduce emissions. In Mechanical fuel injection system, it is not possible to independently control injection start and duration for different operating speeds/powers.