ECD SYSTEM (w/ EGR Cooler Bypass Valve), Diagnostic DTC:P0400

DTC Code DTC Name
P0400 Exhaust Gas Recirculation Flow

DESCRIPTION

The EGR system recirculates exhaust gases, and is controlled to the proper volume to be suitable for all driving conditions. The recirculated gas mixes with the intake air, allowing the EGR system to slow down engine combustion and lower the combustion temperature. This helps reduce NOx emissions.

In order to increase circulation efficiency, the ECM adjusts the lift amount of the EGR valve and throttle valve.

DTC No. DTC Detection Condition Trouble Area
P0400

When either condition below is met:


  • Mass air flow rate is not changed when turning on electric EGR control valve assembly

    (2 trip detection logic)

  • Electric EGR control valve assembly stuck

  • Electric EGR control valve assembly does not move smoothly

  • E-VRV for EGR (EGR control valve assembly)

  • VSV for EGR cut

  • E-VRV for EGR circuit

  • VSV for EGR cut circuit

  • EGR blockage in line between exhaust manifold and intake manifold

  • EFI3 fuse

  • Mass air flow meter

  • Intake system (leaks or blockages)

  • EGR cooler

  • Exhaust system (Exhaust gas leaks)

  • ECM

MONITOR DESCRIPTION



A01KHIJE03

WIRING DIAGRAM

A01KHIEE01

INSPECTION PROCEDURE

Note


  • Inspect the fuses for circuits related to this system before performing the following inspection procedures.

  • After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

Tech Tips

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0400)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Select the following menus: Powertrain / Engine and ECT / DTC.

    4. Read DTCs.

      Result
      Display (DTC Output) Proceed to
      P0400 A
      P0400 and Other DTC B

    B

    GO TO DTC CHART Click here

    A

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ACTIVATE THE VSV FOR EGR CUT)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and warm it up, and the A/C switch and all accessory switches should be off.

    3. Turn the ignition switch off. Wait for 30 seconds and then restart the engine.

    4. Turn the tester on.

    5. Select the following menus: Powertrain / Engine and ECT / Data List / MAF.

    6. Read the MAF value displayed on the tester when engine idling.

    7. Select the following menus: Powertrain / Engine and ECT / Active Test / Activate The VSV for EGR Cut.

    8. Read the MAF value when the VSV for EGR cut is turned from off to on using the Active Test function.

      Tech Tips


      • If idling continues for 15 minutes or more, the EGR valve opening angle target becomes 0% (EGR valve fully closed). As this makes diagnosis impossible, it becomes necessary to run the vehicle or to restart the engine.

      • Before performing the diagnosis, confirm that the EGR valve opening angle target value is not 0%.

      Result
      Active Test Result Proceed to

      Activate The VSV for EGR Cut.:

      off (Open) to on (Close)

      		 MAF value is not changed A
      MAF value is changed B

      Note

      As the numerical values shown below may differ depending on the conditions such as the differences of measuring environments, and the changes of vehicle condition due to aging, do not determine with these values whether acceptable of not.

      Tech Tips

      The problem may be a temporary one, due to the entry of deposits or foreign matter. Please check that there are no deposits or foreign matter in the E-VRV or mass air flow meter.

      Reference
      EGR Valve Condition (Opening) Measuring Condition MAF (Reference)
      Open (55%)

      • Atmosphere pressure: 101 kPa

      • Intake air temperature: 30°C (86°F)

      • Engine coolant temperature: 88°C (190°F)

      		 3.0 to 9.0 g/sec
      Close (0%) 15 to 22 g/sec

    B

    INSPECT ELECTRIC EGR CONTROL VALVE ASSEMBLY (EGR VALVE OPERATION) Click here

    A

  3. CHECK VACUUM HOSES


    1. Check the vacuum hoses.

      OK
      The hoses are not damaged and securely connected

    NG

    REPAIR OR REPLACE VACUUM HOSE

    OK

  4. INSPECT VACUUM REGULATING VALVE (E-VRV FOR EGR)


    1. Inspect the E-VRV for EGR Click here.

      Tech Tips

      Before replacing the E-VRV for EGR, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.


    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY Click here

    OK

  5. INSPECT VACUUM SWITCHING VALVE (VSV FOR EGR CUT)


    1. Disconnect the V2 VSV for EGR cut connector.

    2. A01KGNFE06
      Text in Illustration
      *1 VSV for EGR Cut
      *a Component Side

      Measure the resistance of the VSV for EGR cut.

      Standard resistance
      Tester Connection Specified Condition Specified Condition
      1 - 2 20°C (68°F) 37 to 44 Ω

    3. Check operation of the VSV for EGR cut.


      1. A01KEK1E08
        Text in Illustration
        *1 Filter

        Attach a vacuum pump to port E.

        OK
        Does not vacuum flow from the filter to port E
      2. A01KHPFE07
        Text in Illustration
        *1 Filter

        Apply battery voltage across terminals 1 and 2.

      3. Attach a vacuum pump to port E.

        OK
        Vacuum flows from the filter to port E

      Tech Tips

      Before replacing the VSV for EGR cut, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.


    NG

    REPLACE VACUUM SWITCHING VALVE ASSEMBLY Click here

    OK

  6. INSPECT ELECTRIC EGR CONTROL VALVE ASSEMBLY (EGR VALVE OPERATION)


    1. Inspect the electric EGR control valve assembly. Click here

      OK
      The valve is not stuck and does not have heavy carbon deposit

    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY Click here

    OK

  7. CHECK FOR DEPOSIT (EGR PASSAGE)


    1. Check the deposit conditions in the EGR cooler and the EGR passage.

      OK
      The EGR passage is not stuck and does not have heavy carbon deposit

      Tech Tips

      When performing the check for deposits, check the interior of the EGR valve, the EGR pipe, the EGR cooler, the EGR cooler bypass valve and the entire EGR passage.


    NG

    REPAIR OR REPLACE MALFUNCTIONING PARTS

    OK

  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P0400)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Clear DTCs. Click here

    4. Turn the ignition switch off for 30 seconds or more.

    5. Start the engine and warm it up.

    6. Move the shift lever to 2nd gear and decelerate from a speed of 50 km/h (31 mph) or more (fully closing the accelerator for approximately 5 seconder more).

    7. Select the following menus: Powertrain / Engine and ECT / DTC.

    8. Read DTCs.

      Tech Tips

      When DTC outputs it, malfunction of mass air flow meter is thought.


    NEXT

    END