DTC P0400: Exhaust Gas Recirculation (EGR) System Leak Detected: General Description

The exhaust gas recirculation (EGR) system failure conditions include a sticking lift sensor, restricted passages, and leakage from the external piping. At any specific EGR lift value there is a corresponding air/fuel ratio compensation value. If the air/fuel ratio compensation value is greater than the corresponding EGR lift value, the engine control module (ECM)/powertrain control module (PCM) detects a malfunction and stores a DTC.