P0400
Sistema
Powertrain (Emissions)
Scanner richiesto
Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Exhaust Gas Recirculation Flow Malfunction

Understand P0400, common causes, and the right FOXWELL scanner to diagnose it.

General EGR system fault — flow detected when none expected or control circuit issue.

Sintomi comuni

  • Rough idle
  • Knock under acceleration
  • Check engine light

Cause tipiche

  • Failed EGR valve
  • Carbon blockage
  • Vacuum supply to EGR solenoid
  • DPFE/MAP sensor on Ford EGR

Quale scanner ti serve?

Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Usa dati live e freeze frame prima di sostituire componenti. I codici ABS, SRS e U richiedono spesso uno scanner mult sistema.

Consigli diagnostici

  • Registra il freeze frame quando il codice compare la prima volta
  • Cancella il codice solo dopo aver risolto la causa
  • Controlla i codici pending correlati
  • Verifica che la batteria sia sopra 12,4 V prima di sospettare un sensore

Scanner FOXWELL consigliati

Domande frequenti

Can I diagnose P0400 with a basic code reader?
P0400 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with P0400?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.