DTC P0401:00 [MZR-CD 2.2]

DTC P0401:00	EGR flow insufficient detected
DETECTION CONDITION	• The PCM monitors the difference between target air amount and intake air amount while the EGR system is operating at EGR feedback control. If the difference between target air amount and intake air amount is less than the threshold, the PCM determines that there is a malfunction in the EGR system. • The PCM monitors the difference between target oxygen density and actual oxygen density while the EGR is operating at EGR feedback control. If the difference between target density and actual density is less than the threshold, the PCM determines that there is a malfunction in the EGR system. MONITORING CONDITIONS ― Battery voltage: 8—20 V ― Engine speed: less than 2,500 rpm ― Gear position: 2GR or more ― Vehicle speed: 25—127 km/h {16.0—78.9 mph} ― Intake air temperature: −7 °C {19 °F} or more Diagnostic support note • The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. • PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. • FREEZE FRAME DATA (Mode 2)/Snapshot data is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Air leakage in intake-air system • Intake shutter valve malfunction • Improper operation of EGR valve • EGR cooler bypass valve control solenoid valve malfunction • EGR valve passage malfunction • PCM malfunction

DTC P0401:00

EGR flow insufficient detected

DETECTION CONDITION

• The PCM monitors the difference between target air amount and intake air amount while the EGR system is operating at EGR feedback control. If the difference between target air amount and intake air amount is less than the threshold, the PCM determines that there is a malfunction in the EGR system.

• The PCM monitors the difference between target oxygen density and actual oxygen density while the EGR is operating at EGR feedback control. If the difference between target density and actual density is less than the threshold, the PCM determines that there is a malfunction in the EGR system.

MONITORING CONDITIONS

― Battery voltage: 8—20 V

― Engine speed: less than 2,500 rpm

― Gear position: 2GR or more

― Vehicle speed: 25—127 km/h {16.0—78.9 mph}

― Intake air temperature: −7 °C {19 °F} or more

Diagnostic support note

• The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.

• PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Air leakage in intake-air system

• Intake shutter valve malfunction

• Improper operation of EGR valve

• EGR cooler bypass valve control solenoid valve malfunction

• EGR valve passage malfunction

• PCM malfunction

STEP	INSPECTION	ACTION
1	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?	Yes	Go to the next step.
No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND/OR DTC • Switch the ignition to off, then to ON (engine off). • Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].) • Are any other PENDING CODEs and/or DTCs present?	Yes	Go to the applicable PENDING CODE or DTC inspection. (See DTC TABLE [MZR-CD 2.2].)
No	Go to the next step.
4	INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE • Inspect the intake-air system for air leakage between MAF sensor and turbocharger. • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.
No	Go to the next step.
5	INSPECT INTAKE SHUTTER VALVE OPERATION • Perform the Intake Shutter Valve Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR-CD 2.2].) • Does the intake shutter valve operate properly?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.
6	INSPECT EGR VALVE OPERATION • Perform the EGR Valve Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR-CD 2.2].) • Does the EGR valve operate properly?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.
7	INSPECT EGR COOLER BYPASS VALVE OPERATION • Perform the EGR Cooler Bypass Valve Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR-CD 2.2].) • Does the EGR cooler bypass valve operate properly?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.
8	INSPECT EGR VALVE PASSAGE • Switch the ignition to off. • Remove the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [MZR-CD 2.2].) • Visually inspect the EGR valve gasket. • Is the gasket normal?	Yes	Go to the next step.
No	Install the gasket correctly, then go to the next step.
9	VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [MZR-CD 2.2].) • Perform the Repair Verification Drive Mode. (See OBD DRIVE MODE [MZR-CD 2.2].) • Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [MZR-CD 2.2].)
No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZR-CD 2.2].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR-CD 2.2].)
No	DTC troubleshooting completed.

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED

• Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?

Yes

Go to the next step.

Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.

VERIFY RELATED SERVICE INFORMATION AVAILABILITY

• Verify related Service Information availability.

• Is any related Service Information available?

Yes

Perform repair or diagnosis according to the available Service Information.

• If the vehicle is not repaired, go to the next step.

Go to the next step.

VERIFY RELATED PENDING CODE AND/OR DTC

• Switch the ignition to off, then to ON (engine off).

• Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.

(See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].)

• Are any other PENDING CODEs and/or DTCs present?

Yes

Go to the applicable PENDING CODE or DTC inspection.

(See DTC TABLE [MZR-CD 2.2].)

Go to the next step.

INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE

• Inspect the intake-air system for air leakage between MAF sensor and turbocharger.

• Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.

Go to the next step.

INSPECT INTAKE SHUTTER VALVE OPERATION

• Perform the Intake Shutter Valve Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR-CD 2.2].)

• Does the intake shutter valve operate properly?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.

INSPECT EGR VALVE OPERATION

• Perform the EGR Valve Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR-CD 2.2].)

• Does the EGR valve operate properly?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.

INSPECT EGR COOLER BYPASS VALVE OPERATION

• Perform the EGR Cooler Bypass Valve Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR-CD 2.2].)

• Does the EGR cooler bypass valve operate properly?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.

INSPECT EGR VALVE PASSAGE

• Switch the ignition to off.

• Remove the EGR valve.

(See EGR VALVE REMOVAL/INSTALLATION [MZR-CD 2.2].)

• Visually inspect the EGR valve gasket.

• Is the gasket normal?

Yes

Go to the next step.

Install the gasket correctly, then go to the next step.

VERIFY DTC TROUBLESHOOTING COMPLETED

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

(See AFTER REPAIR PROCEDURE [MZR-CD 2.2].)

• Perform the Repair Verification Drive Mode.

(See OBD DRIVE MODE [MZR-CD 2.2].)

• Is the PENDING CODE for this DTC present?

Yes

Replace the PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [MZR-CD 2.2].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform the “AFTER REPAIR PROCEDURE”.

(See AFTER REPAIR PROCEDURE [MZR-CD 2.2].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [MZR-CD 2.2].)

DTC troubleshooting completed.