DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient Detected (4JJ3 without DPD)

1. DTC P0401 description

The EGR valve is equipped with a microprocessor. The internal microprocessor controls the EGR motor according to the commands from the ECM. The ECM calculates the desired EGR position based on the driving condition of the engine, and sends it to the EGR valve via CAN. The EGR valve lift amount is calculated by the microprocessor inside the EGR valve, and is sent to the ECM via CAN. When the proper enabling conditions are met, the ECM opens the EGR valve while monitoring the MAF signal. An expected MAF difference should be detected between the closed and open positions of the valve. If the ECM detects a MAF difference that is equal to or less than expected, the DTC is set. This DTC only runs once per ignition cycle within the effective conditions.

2. Condition for setting DTC P0401

Condition for running the DTC

The battery voltage is 9 to 16 V.
The ignition switch is ON.
The engine is running.
DTCs P003A, P0045, P0048, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0122, P0123, P0403, P0560, P060B, P0638, P0641, P0651, P0697, P2227, P2228, P2229, U0001, U0074, U010A, and U0110 are not set.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P003A Turbocharger Boost Control Solenoid Performance".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0045 Turbocharger Boost Control Solenoid Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0048 Turbocharger Control Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0102 Mass Air Flow Circuit Low Input".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0103 Mass Air Flow Circuit High Input".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0112 Intake Air Temperature Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0113 Intake Air Temperature Sensor Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0116 Engine Coolant Temperature Sensor Circuit Range/Performance".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0117 Engine Coolant Temperature Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0118 Engine Coolant Temperature Sensor Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0122 Throttle Position Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0123 Throttle Position Sensor Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0403 Exhaust Gas Recirculation (EGR) Motor Control Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0560 System Voltage".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P060B Internal Control Module A/D Processing Performance".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0638 Throttle Actuator Control Range/Performance".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0641 Sensor Reference Voltage 1 Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0651 Sensor Reference Voltage 2 Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0697 Sensor Reference Voltage 3 Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P2227 Barometric Pressure Circuit Range/Performance".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P2228 Barometric Pressure Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P2229 Barometric Pressure Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC U0001 High Speed CAN Communication Bus".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC U0074 Control Module Communication Bus Off - Local CAN".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC U010A Lost Communication With Exhaust Gas Recirculation (EGR) Control Module".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC U0110 Lost Communication with VNT System".

Condition for setting the DTC

When the EGR control is in the feedback mode, the ECM detects that the EGR flow rate is low.

3. Action taken when DTC P0401 sets

Euro4: The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type B (Euro4).
Except Euro4: The ECM illuminates the check engine warning light. Refer to Action taken when DTC sets - Type B (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC type definitions".

4. Condition for clearing DTC P0401

Euro4: Refer to Condition for clearing the MIL/DTC - Type A or Type B (Euro4).
Except Euro4: Refer to Condition for clearing the check engine warning light/DTC - Type A or Type B (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC type definitions".