Enhanced Testing
P0401 - Exhaust Gas Recirculation Flow Insufficient Detected
General Description
The Exhaust Gas Recirculation (EGR) system is designed to introduce exhaust gas into the combustion cycle. This lowers combustion temperatures and reduces the formation of oxides of nitrogen. The amount and timing of exhaust gas introduced into the combustion cycle varies by such factors as engine speed, engine vacuum, exhaust system back pressure, coolant temperature and throttle position.
DTC Description
If the pressure change of intake manifold is less than 26 mmHg (AT) when the EGR S/V is operated, the ECM determines that a fault exists and a DTC is stored.
Detecting Condition
Wiring Schematic