Powertrain
generic / SAE
P0400
Exhaust Gas Recirculation Flow Malfunction
A general fault has been detected in the exhaust gas recirculation (EGR) system. EGR routes a portion of exhaust back into the intake to reduce combustion temperature and NOx emissions. Most EGR codes today are caused by carbon buildup blocking the valve.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / 00
Possible causes
- EGR valve clogged with carbon high
- Intake EGR passages blocked medium
- DPFE / EGR position sensor failed low
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 60–800 €
- Estimated time: 1–5 h
- Component: egr valve
- Component: egr cooler
- Component: dpfe sensor
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012