P0401

The scan tool indicates Diagnostic Trouble Code (DTC) P0401: Insufficient flow in the Exhaust Gas Recirculation (EGR) system.

Description
Deterioration (clogging, leakage, etc.) in the EGR line or EGR valve is detected by means of monitoring the changes in MAP before and after the operation of the EGR valve.
If deterioration has been detected during two consecutive driving cycles, the MIL will come on and DTC P0401 will be stored.

NOTE: If DTC P1491 is stored at the same time as DTC P0401, troubleshoot DTC P1491 first, then reset the ECM and recheck for DTC P0401.

Possible Causes
- Clogging, leakage in the EGR line
- Faulty EGR valve