What is the meaning of OBD-II p0402 code , and what are the possible causes and how to solve this issue?
OBD-II code P0402 is a generic code that indicates an issue with the Exhaust Gas Recirculation (EGR) system in your vehicle. The code definition is "Excessive EGR Flow".
The possible causes for this code to be triggered include:
A faulty EGR valve
A clogged EGR passage
A vacuum leak in the EGR system
A malfunctioning PCM (Powertrain Control Module) or EGR control solenoid valve
A damaged or corroded EGR valve connector
A problem with the EGR valve control circuit, such as a short circuit or an open circuit
To solve this issue, a mechanic would typically perform a visual inspection of the EGR system and its components, including the EGR valve, vacuum solenoid, and wiring. If no obvious problems are found, they may perform a smoke test of the EGR system to check for clogs or other issues. In some cases, further diagnosis may be required to isolate the cause of the code, such as checking the EGR control circuit for proper operation. If the EGR valve is found to be faulty, it will typically need to be replaced.