DTC P0401:00 [MZR-CD (RF Turbo)]

id0102f1704200

DTC P0401:00

EGR flow insufficient detected
DETECTION CONDITION
•  The PCM monitors the difference between the target air amount and intake air amount while the EGR system is operating at EGR feedback control. If the difference between the target air amount and the 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 the target density and actual density is less than the threshold, the PCM determines that there is a malfunction in the EGR system.
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 the first drive cycle.
•  FREEZE FRAME DATA is available.
•  DTCs are stored in the PCM memory.
POSSIBLE CAUSE
•  Air leakage in intake air system between MAF sensor and turbocharger
•  EGR valve malfunction
•  Intake shutter valve malfunction
•  EGR gasket malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA on repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
•  If vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT FOR OTHER DTCs
•  Connect the M-MDS to the DLC-2.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Switch the ignition to ON (Engine off).
•  Have other DTCs been stored?
Yes
Repair the circuit malfunction for the applicable DTCs.
(See DTC TABLE [MZR-CD (RF Turbo)].)
No
Go to the next step.
4
INSPECT INTAKE AIR SYSTEM FOR AIR LEAKAGE
•  Inspect intake-air system for air leakage between MAF sensor and turbocharger.
•  Is there any air leakage detected?
Yes
Repair or replace for air leakage, then go to Step 8.
No
Go to the next step.
5
INSPECT INTAKE SHUTTER VALVE OPERATION
•  Perform the Intake Shutter Valve Operation Inspection.
•  Does the intake shutter valve operate properly?
Yes
Go to the next step.
No
Repair or replace malfunctioning part, according to inspection result.
6
INSPECT EGR VALVE OPERATION
•  Perform the EGR Valve Operation Inspection.
•  Does EGR valve operate properly?
Yes
Go to the next step.
No
Replace the EGR valve, then go to Step 8.
(See EGR COOLER REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
7
INSPECT EGR VALVE PASSAGE
•  Switch the ignition to off.
•  Remove the EGR valve.
•  Is the gasket normal?
Yes
Go to the next step.
No
Install the gasket correctly, then go to the next step.
8
VERIFY TROUBLESHOOTING OF DTC P0401:00 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Connect the M-MDS to the DLC-2.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the Repair Verification Drive Mode.
•  Is the PENDING CODE for this DTC present?
Yes
Go to the next step.
No
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
9
VERIFY AFTER REPAIR PROCEDURE
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR-CD (RF Turbo)].)
No
Troubleshooting completed.