LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2019 >> GX 460 Luxury >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes) (3 Of 7) >> SFI System >> DTC P0401: Exhaust Gas Recirculation Flow Insufficient Detected [08/2015 - 08/2018] >> Confirmation Driving Pattern
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Confirmation Driving Pattern

Fig 1: Confirmation Driving Pattern Graph
GTY622830Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. Connect the Techstream to the DLC3.
  2. Turn the engine switch on (IG) and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (Refer to DTC CHECK / CLEAR [08/2015 - ] ).
  4. Turn the engine switch off and wait for 30 seconds.
  5. Turn the engine switch on (IG) and turn the Techstream on [A].
  6. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [B].

    HINT: 

    The A/C switch and all accessory switches should be off and the shift lever should be in P or N.

  7. Drive the vehicle at 60 km/h (37 mph) for 5 minutes or more [C].
    WARNING:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  8. Idle the engine for 30 seconds or more [D].
  9. Drive the vehicle at 60 km/h (37 mph) and shift the transmission to 2nd gear [E].
    WARNING:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  10. Perform fuel cut operation for 5 seconds or more with the accelerator pedal fully released [F].

    HINT: 

    When "Idle Fuel Cut" in the Data List is ON, fuel cut is operating.

  11. Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / Exhaust Gas Recirculation/VVT / Current [G].
  12. Check that the Exhaust Gas Recirculation/VVT / Current monitor is Complete.

    HINT: 

    If the monitor is Incomplete, perform the driving pattern again.

  13. Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / Exhaust Gas Recirculation/VVT / Details / EGR FLOW INSUFFICIENCY / Details.
  14. Check the test Details (EGR FLOW INSUFFICIENCY).

    HINT: 

    Make sure that the values are between MIN and MAX.

  15. If the monitor is still Incomplete, perform the following procedure.
  16. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  17. Read the pending DTCs.

    HINT: 

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  18. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  19. Input the DTC: P0401.
  20. Check the DTC judgment result.
    Techstream 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
    N/A
    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT: 

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the DTC judgment result is INCOMPLETE or N/A and no pending DTC is output, drive the vehicle again at 60 km/h (37 mph) and shift the transmission to 2nd gear, perform fuel cut operation for 5 seconds or more with the accelerator pedal fully released, and then check the DTC judgment result.
  21. If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (Refer to DTC CHECK / CLEAR [08/2015 - ] ).

    HINT: 

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.
scientia non olet · About LEMON Manuals