The P0402 trouble code is associated with Exhaust Gas Recirculation (EGR) Flow Excessive Detected, indicating that the flow of exhaust gases being recirculated into the engine is above the expected level.
Exhaust Gas Recirculation Flow Excessive Detected
Code symptoms P0402.
1. Illuminated “Check Engine” or “Service Engine Soon” light on the dashboard.
2. Poor engine performance.
3. Increased emissions.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0402.
1. Faulty EGR valve.
2. EGR valve stuck in the open position.
3. Clogged or restricted EGR passages.
4. Wiring or connection issues in the EGR system.
5. Problems with the Engine Control Module (ECM).
Code Solutions P0402.
1. Inspect and, if necessary, replace the malfunctioning EGR valve.
2. Ensure the EGR valve is not stuck in the open position.
3. Inspect and, if necessary, clean or replace clogged or restricted EGR passages.
4. Inspect and repair any faults in the wiring or connections of the EGR system.
5. If ECM issues are suspected, consult a qualified technician for diagnosis and potential reprogramming or replacement.