What does P0408 fault code mean? Fault code P0408 solution.

The fault code P0408 is described in detail as follows: System scope of the fault: emission control applicable models: all automobile manufacturers Chinese meaning explanation: exhaust gas recirculation sensor B- circuit voltage Gao Yingwen meaning: there is no knowledge about the fault code P0408 at present 1. The position and function of the exhaust gas recirculation sensor on the vehicle: a) The exhaust gas recirculation sensor is usually integrated with the exhaust gas recirculation valve, located on the right side of the intake manifold and close to the throttle body. B) The function of the exhaust gas recirculation sensor is to detect the opening of the exhaust gas recirculation valve and send a signal to PCM to determine the amount of exhaust gas recirculation. 2. The type, structure principle and influence of the exhaust gas recirculation sensor: a) The exhaust gas recirculation sensor is a three-wire system, one is a 5V power line, one is a ground line and the other is a signal line. B) The exhaust gas recirculation sensor is a variable resistor (potentiometer). C) Exhaust gas recirculation sensor is an important signal information to reduce emissions and fuel consumption. Cause and effect: 1. The fault code explains that the function of the exhaust gas recirculation (EGR) system is to introduce a small amount of exhaust gas into the intake manifold under the specific working conditions of the engine. The existence of these exhaust gases reduces the temperature and pressure of the combustion chamber, thus reducing the emission of nitrogen oxide pollutants. This fault code will occur if the electronic control unit (ECU) detects that the signal voltage of the exhaust gas recirculation (EGR) sensor is higher than the calibrated maximum value. Suggested solution: 1. Cause of failure: a) Whether the exhaust gas recirculation (EGR) system pipeline leaks (if it leaks, there will be abnormal sound); B) Whether the solenoid valve of exhaust gas recirculation (EGR) system is aging or damaged; C) Whether the air pump, diverter valve, check valve and pressure relief valve of c)EGR system are faulty; D) Whether the solenoid valve of d)EGR system and its circuit are short-circuited, open-circuited or in poor contact; E) Whether the sensors affecting the exhaust gas recirculation (EGR) system are abnormal (such as intake pressure, coolant temperature, oxygen sensor, etc.). ).); F) f) whether the ECU is faulty. 2. Treatment method: a) Check the exhaust gas recirculation (EGR) system pipeline for cracks and leaks, and if so, repair or replace it. If the fault is not solved or there are other faults, please find professional technicians. B) Pay attention to cleaning the air filter regularly at ordinary times. If the vehicle often wades in water, the valve of EGR system may rust and get stuck due to the inhaled moisture, so the vehicle should avoid wading as much as possible.