What is the solution for the P0401 trouble code?

[LaCarson]

P0401 trouble code indicates that the exhaust gas recirculation valve A has detected insufficient flow. Possible causes include a faulty exhaust gas sensor, damaged circuit connectors, a malfunctioning exhaust gas recirculation valve, clogged EGR valve pipelines, or issues with the electronic control module, which can trigger the P0401 trouble code. The solution is to troubleshoot the exhaust gas recirculation system and clear the trouble code. More details are as follows: 1. After troubleshooting the vehicle, it is often necessary to clear the trouble code. When clearing the trouble code, it must be done according to the specified method for the vehicle model. Be careful not to arbitrarily remove the negative ground cable of the battery to clear the trouble code. After clearing the trouble code, it is recommended to clean and replace the exhaust EGR control valve. 2. The function of the exhaust gas recirculation (EGR) system is to introduce a small amount of exhaust gas into the intake manifold when the engine is operating under high load. The presence of these exhaust gases reduces the temperature and pressure in the combustion chamber, thereby decreasing the emission of nitrogen oxide pollutants. When the vehicle is driving normally and steadily, and the exhaust gas recirculation system (EGR) is open, if the electronic control unit (ECU) detects that the flow of exhaust gas recirculation (EGR) is lower than the estimated value based on other information, this trouble code will appear.