P0402 - EXHAUST GAS RECIRCULATION FLOW EXCESSIVE DETECTED

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.

• The malfunction indicator light (Check Engine) lights up.
• Instability of the vehicle at idle speed.

When the diagnostic code P0402 OBDII is set, it means that one or more of the following has occurred:

• Possibly the Differential Pressure Sensor is defective.
• Lack of vacuum in the Exhaust Gas Recirculation valve.
• Exhaust Gas Recirculation valve blocked, possibly by carbon.
• Maybe the EGR valve is defective.

Before the fault code P0402 OBD2 you must do the following for its correct correction:

• Check the DPF sensor voltage, you must perform the check, both when it is idling, and when the Exhaust Gas Recirculation valve is open.
• Compare with the manufacturer's specifications, and if they are not within them, change the Differential Pressure Sensor.
• Change the Exhaust Gas Recirculation (EGR) valve.