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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 57 (Engine Control System (A25A-FXS) - Diagnostic Codes (P0325-P0400)) >> SFI System >> DTC P0400-00: Exhaust Gas Recirculation "A" Flow; DTC P0401-9C: Exhaust Gas Recirculation "A" Low / Insufficient Flow; DTC P0402-9B: Exhaust Gas Recirculation "A" High/Excessive Flow [10/2022 - 11/2023] >> Procedure

DTC P0400-00: Exhaust Gas Recirculation "A" Flow; DTC P0401-9C: Exhaust Gas Recirculation "A" Low / Insufficient Flow; DTC P0402-9B: Exhaust Gas Recirculation "A" High/Excessive Flow [10/2022 - 11/2023]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0400-00, P0401-9C, P0402-9B) 
    1. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTC P0400-00, P0401-9C or P0402-9B is output A
      DTC P0400-00, P0401-9C or P0402-9B and other DTCs are output B

      HINT: 

      If any DTCs other than P0400-00, P0401-9C or P0402-9B are output, troubleshoot those DTCs first.

    Result: 

    B 

    GO TO DTC CHART  . Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2022 - 11/2023]

    Result: 

    A 

    See step  2

  2. READ VALUE USING GTS (INTAKE MANIFOLD ABSOLUTE PRESSURE) 
    1. Read the value of Intake Manifold Absolute Pressure.

      Powertrain > Engine > Data List 

      Tester Display
      Intake Manifold Absolute Pressure

      Standard

      GTS Display Specified Condition
      Intake Manifold Absolute Pressure 80 to 110 kPa (11.6 to 15.95 psi)

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR 

    Refer to REMOVAL [12/2019 - ]

    Result: 

    OK 

    See step  3

  3. PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION) 
    1. Put the engine in Inspection Mode (Maintenance Mode).

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode
    2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature

      HINT: 

      The A/C switch and all accessories should be off.

    3. According to the display on the GTS, compare the values of Data List item Intake Manifold Absolute Pressure before and while performing the Active Test.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the EGR Step Position
      Data List Display
      Intake Manifold Absolute Pressure
      Engine Independent
      NOTE:
      • Make sure that the value of Data List item Engine Independent is "Operate" while performing the Active Test.
      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.
      • Be sure to return the EGR valve to step 0 when the Active Test is completed.
      • Do not open the EGR valve 30 steps or more during the Active Test.

      Standard

      The value of Intake Manifold Absolute Pressure changes according to the EGR valve step set by the Active Test.

      Data List Control the EGR Step Position (Active Test)
      Before Active Test
      (Engine idling)      		 0 Steps 0 to 30 Steps
      (Engine idling)
      Intake Manifold Absolute Pressure 20 to 40 kPa (2.9 to 5.8 psi) (EGR valve is fully closed) Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

      HINT: 

      • If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
      • While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

      Result

      Result Proceed to
      Before performing the Active Test (while the engine is idling), the value of Intake Manifold Absolute Pressure is not between 20 to 40 kPa (2.9 to 5.8 psi). A
      When performing the Active Test to change the EGR valve step between 0 (EGR valve fully closed) and 30, the value of Intake Manifold Absolute Pressure changes less than 10 kPa (1.45 psi). B
      Other than above C

    Result: 

    B 

    See step  6

    Result: 

    C 

    See step  12

    Result: 

    A 

    See step  4

  4. CHECK INTAKE SYSTEM 
    1. Check the intake system for vacuum leaks.

      Refer to ON-VEHICLE INSPECTION [12/2019 - ]

      OK

      No leaks from intake system.

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the intake system.

      Refer to INITIALIZATION [10/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE INTAKE SYSTEM 

    Result: 

    OK 

    See step  5

  5. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly.

      Refer to REMOVAL [10/2022 - 11/2023]

    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

      HINT: 

      Perform "Inspection After Repair" after replacing the EGR valve assembly.

      Refer to INITIALIZATION [10/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR 

    Refer to REMOVAL [12/2019 - ]

    Result: 

    NG 

    REPLACE EGR VALVE ASSEMBLY 

    Refer to REMOVAL [10/2022 - 11/2023]

  6. REPLACE EGR VALVE ASSEMBLY 

    Refer to REMOVAL [10/2022 - 11/2023]

    HINT: 

    Perform "Inspection After Repair" after replacing the EGR valve assembly.

    Refer to INITIALIZATION [10/2021 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  7

  7. CLEAR DTC 
    1. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    2. Turn the ignition switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  8

  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P0400-00, P0401-9C OR P0402-9B) 
    1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    2. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    3. Input the DTC: P0400-00, P0401-9C or P0402-9B.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P0400-00, P0401-9C or P0402-9B is output)      		 B

    Result: 

    A 

    END 

    Result: 

    B 

    See step  9

  9. REPLACE EGR COOLER ASSEMBLY 

    Refer to REMOVAL [10/2022 - 11/2023]

    HINT: 

    • If any of the EGR system related pipes (EGR pipe, exhaust manifold, etc.) are cracked, damaged or clogged, replace them as necessary.
    • Perform "Inspection After Repair" after replacing the EGR system.

      Refer to INITIALIZATION [10/2021 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  10

  10. CLEAR DTC 
    1. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    2. Turn the ignition switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  11

  11. CHECK WHETHER DTC OUTPUT RECURS (DTC P0400-00, P0401-9C OR P0402-9B) 
    1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    2. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness

      Result

      GTS Display Description
      NORMAL
      • DTC judgment completed
      • System normal
      ABNORMAL
      • DTC judgment completed
      • System abnormal
      INCOMPLETE
      • DTC judgment not completed
      • Perform driving pattern after confirming DTC enabling conditions
    3. Input the DTC: P0400-00, P0401-9C or P0402-9B.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

  12. CLEAR DTC 
    1. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    2. Turn the ignition switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  13

  13. CHECK WHETHER DTC OUTPUT RECURS (DTC P0400-00, P0401-9C OR P0402-9B) 
    1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    2. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    3. Input the DTC: P0400-00, P0401-9C or P0402-9B.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P0400-00, P0401-9C or P0402-9B is output)      		 B

      HINT: 

      Perform "Inspection After Repair" after replacing the EGR valve assembly.

      Refer to INITIALIZATION [10/2021 - ]

    Result: 

    A 

    END 

    Result: 

    B 

    REPLACE EGR VALVE ASSEMBLY 

    Refer to REMOVAL [10/2022 - 11/2023]

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