The P0401 trouble code is associated with Exhaust Gas Recirculation (EGR) Flow Insufficient Detected, indicating that the flow of exhaust gases being recirculated into the engine is below the expected level.
Exhaust Gas Recirculation Flow Insufficient Detected
Code symptoms P0401.
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 P0401.
1. Clogged or restricted EGR passages.
2. Faulty EGR valve.
3. EGR valve stuck open.
4. Wiring or connection issues in the EGR system.
5. Problems with the Engine Control Module (ECM).
Code Solutions P0401.
1. Inspect and, if necessary, clean or replace clogged or restricted EGR passages.
2. Check and replace the EGR valve if it’s faulty.
3. Ensure the EGR valve is not stuck open.
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.