DTC P0401 [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)]

id0102c4815300

DTC P0401

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.
POSSIBLE CAUSE
•  EGR valve malfunction
•  Intake shutter valve malfunction
•  Boost sensor malfunction
•  Turbocharger mechanical 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 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
INSPECT FOR OTHER DTCs
•  Connect the M-MDS to the DLC-2.
•  Clear the DTC from the PCM memory using the M-MDS.
•  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 [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)].)
No
Go to the next step.
4
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.
5
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 10.
(See EGR SYSTEM REMOVAL/INSTALLATION [WL-C, WE-C].)
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 10.
7
INSPECT GUIDE BLADE ACTUATOR
•  Inspect the guide blade actuator.
•  Is the guide blade actuator normal?
Yes
Go to the next step.
No
Replace the turbocharger, then go to Step 10.
(See EXHAUST SYSTEM REMOVAL/INSTALLATION [WL-C, WE-C].)
8
INSPECT TURBOCHARGER
•  Inspect the turbocharger.
•  Is the turbocharger normal?
Yes
Go to the next step.
No
Replace the turbocharger, then go to Step 10.
(See EXHAUST SYSTEM REMOVAL/INSTALLATION [WL-C, WE-C].)
9
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.
10
VERIFY TROUBLESHOOTING OF DTC P0401 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 [WL-C, WE-C].)
(See PCM REMOVAL/INSTALLATION (U.K. Specs.) [WL-C, WE-C].)
11
VERIFY AFTER REPAIR PROCEDURE
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)].)
No
Troubleshooting completed.