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DTC P0401 [MZR-CD (RF Turbo)]

id0102f1815300

DTC P0401 | EGR flow insufficient detected
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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 • MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for the same malfunction has been stored in PCM. • PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle. • FREEZE FRAME DATA is available. • DTC is stored in the PCM memory.
POSSIBLE CAUSE | • EGR valve malfunction • Intake shutter valve malfunction • Boost sensor malfunction • EGR gasket malfunction • PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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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 REPAIR INFORMATION AVAILABILITY • Verify related service bulletins and/or on-line repair information availability. • Is any related repair information available? | Yes | Perform repair or diagnosis according to the available repair information. • If the vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | INSPECT FOR OTHER DTCs • Connect the WDS or equivalent to the DLC-2. • Clear the DTC from the PCM memory using the WDS or equivalent. • Turn the engine switch to the ON position. (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 SHUTTER VALVE OPERATION • Perform the Intake Shutter Valve Operation Inspection. (See 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.
5 | INSPECT EGR VALVE OPERATION • Perform the EGR Valve Operation Inspection. (See 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 VALVE REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
6 | INSPECT BOOST SENSOR MALFUNCTION • Inspect the boost sensor. • Is the boost sensor normal? | Yes | Go to the next step.
No | Replace the boost sensor, then go to Step 8.
7 | INSPECT EGR VALVE PASSAGE • Turn the engine switch 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 COMPLETED • Make sure to reconnect all disconnected connectors. • Connect the WDS or equivalent to the DLC-2. • Clear the DTC from the PCM memory using the WDS or equivalent. • Perform the Repair Verification Drive Mode. (See OBD DRIVE MODE [MZR-CD (RF Turbo)].) • 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.