Powertrain
generic / SAE
P0401
Exhaust Gas Recirculation Flow Insufficient Detected
When the ECU commands EGR open, the actual flow measured by the DPFE sensor or the resulting MAP/MAF change is below threshold. By far the most common cause is a carboned-up EGR valve or blocked intake passages.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / 01
Possible causes
- EGR valve clogged or stuck closed high
- Intake EGR passages blocked with carbon high
- Vacuum line to EGR (vacuum-actuated valves) cracked medium
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 60–700 €
- Estimated time: 1–5 h
- Component: egr valve
- Component: egr passages
- Component: dpfe sensor
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012