DTC P0401: EGR System, Insufficient Flow: Condition

DTC is set when the difference in intake manifold pressure between open EGR and closed EGR is too small. This is an intermittent monitor. MIL is illuminated when Powertrain Control Module (PCM) detects malfunction during 2 consecutive drive cycles. Possible causes are:

• EGR valve malfunction.
• EGR boost sensor malfunction.
• EGR boost sensor solenoid valve malfunction.
• EGR valve base gasket improperly installed.
• Powertrain Control Module (PCM) malfunction.