P0401Moderate

Code P0401 — Exhaust Gas Recirculation Flow Insufficient

The P0401 code indicates that the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust gas back into the intake manifold. The EGR system reduces NOx emissions by recirculating a portion of exhaust gas. When the ECM commands EGR flow and detects insufficient flow via the MAP sensor or EGR position sensor, P0401 is set.

Common Causes

  • ▸Clogged EGR valve
  • ▸Faulty EGR valve solenoid
  • ▸Blocked EGR passages
  • ▸Faulty differential pressure sensor

Related Codes

P0400P0402P0403P0404