The Exhaust Gas Recirculation (EGR) system is one of the emission components of the vehicle. It aims to reduce the temperature and fuel pressure. In addition, with this system you have greater control of nitrogen oxides.
The Exhaust Gas Recirculation (EGR) system usually has 3 parts: the EGR valve, the actuator solenoid and the Differential Pressure Feedback Sensor (DPF). These components work in harmony and deliver the necessary amount of recirculation in consequence of the temperature and load of the motor.
When the DTC code P0402 is set, it indicates that the PCM has determined that there is a high amount of EGR.