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Home >> Lexus >> 2023 >> ES 250 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (A25A-FKS) - Diagnostic Codes (06 Of 12) >> SFI System >> DTC P050A-00: Cold Start Idle Control System Performance [08/2020 - 08/2021] >> Procedure
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DTC P050A-00: Cold Start Idle Control System Performance [08/2020 - 08/2021]: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A-00) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Trouble Codes.
    5. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTC P050A-00 is output A
      DTC P050A-00 and other DTCs are output B

      HINT: 

      If any DTCs other than P050A-00 are output, troubleshoot those DTCs first.

    Result: 

    B 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2020 - 08/2021] 

    Result: 

    A 

    See step  2

  2. READ VALUE USING TECHSTREAM (FUEL TRIM) 

    HINT: 

    Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter sub-assembly.

    1. Connect the Techstream to the DLC3.
    2. Start the engine.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Short FT B1S1 and Long FT B1S1.

      Powertrain > Engine > Data List 

      Tester Display
      Short FT B1S1
      Long FT B1S1
    5. Read the values displayed on the Techstream at engine idle.
    6. Add the Short FT B1S1 and Long FT B1S1 values to obtain the total fuel trim.

      Standard

      Techstream Display Specified Condition
      Total of Short FT B1S1 and Long FT B1S1 Between -20 and 20%

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  3

  3. INSPECT THROTTLE BODY WITH MOTOR ASSEMBLY (VISUALLY CHECK THROTTLE VALVE) 
    1. Check for foreign matter between the throttle valve and housing. If necessary, clean the throttle body with motor assembly. Also, check that the throttle valve moves smoothly.

      OK

      Throttle valve is not contaminated with foreign matter and moves smoothly.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  6

    Result: 

    OK 

    See step  4

  4. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.

      HINT: 

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

    5. Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Engine Speed, Intake Manifold Absolute Pressure and Coolant Temperature.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the EGR Step Position
      Data List Display
      Engine Speed
      Intake Manifold Absolute Pressure
      Coolant Temperature
    6. Check the engine idling condition and Intake Manifold Absolute Pressure values in the Data List while performing the Active Test.
      NOTE:
      • 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.

      OK

      The value of Intake Manifold Absolute Pressure and Engine Speed change in response to EGR step position.

      Standard

      - Control the EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Idling condition Steady idling Idling changes from steady to rough idling or engine stalls
      Intake Manifold Absolute Pressure
      (Data List)      		 Intake Manifold Absolute Pressure value is 20 to 40 kPa(abs)
      (2.9 to 5.8 psi(abs))
      (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: 

      During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  14

    Result: 

    NG 

    See step  5

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

      Refer to REMOVAL [08/2020 - 08/2021]

    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  14

    Result: 

    NG 

    See step  17

  6. REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY 
    1. Replace the throttle body with motor assembly.

      Refer to REMOVAL [08/2020 - ]

      HINT: 

      Perform "Inspection After Repair" after replacing the throttle body with motor assembly.

      Refer to INITIALIZATION [08/2020 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  7. CHECK PCV VALVE AND HOSE CONNECTIONS 
    GTY753568Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Check the PCV hose connections.
    2. Check the PCV valve.

      Refer to INSPECTION [08/2020 - ]

      OK

      PCV hose and PCV valve are connected correctly and are not damaged.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  20

    Result: 

    OK 

    See step  8

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

      Refer to PROCEDURE - Step 1

      OK

      No leaks from intake system.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  19

    Result: 

    OK 

    See step  9

  9. CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 
    1. Visually check that the air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.

      OK

      The air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  18

    Result: 

    OK 

    See step  10

  10. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.

      HINT: 

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

    5. Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Engine Speed, Intake Manifold Absolute Pressure and Coolant Temperature.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the EGR Step Position
      Data List Display
      Engine Speed
      Intake Manifold Absolute Pressure
      Coolant Temperature
    6. Check the engine idling condition and Intake Manifold Absolute Pressure values in the Data List while performing the Active Test.
      NOTE:
      • 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.

      OK

      The value of Intake Manifold Absolute Pressure and Engine Speed change in response to EGR step position.

      Standard

      - Control the EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Idling condition Steady idling Idling changes from steady to rough idling or engine stalls
      Intake Manifold Absolute Pressure
      (Data List)      		 Intake Manifold Absolute Pressure value is 20 to 40 kPa(abs)
      (2.9 to 5.8 psi(abs))
      (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: 

      During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  12

    Result: 

    NG 

    See step  11

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

      Refer to REMOVAL [08/2020 - 08/2021]

    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  17

    Result: 

    OK 

    See step  12

  12. PERFORM ACTIVE TEST USING TECHSTREAM (CHECK VVT SYSTEM) 
    1. Operate the VVT system through the Active Test, and check if the VVT system is operating normally.
      1. Perform the Active Test, referring to DTC P0011-00 Procedure (VVT-iE system for intake camshaft).

        Refer to DTC P0011-00: Camshaft Position "A" - Timing Over-Advanced or System Performance Bank 1 [08/2020 - 08/2021]

      2. Perform the Active Test, referring to DTC P0014-00 Procedure (VVT-i system for exhaust camshaft).

        Refer to PROCEDURE - Step 14

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  16

    Result: 

    OK 

    See step  13

  13. READ VALUE USING TECHSTREAM (MASS AIR FLOW SENSOR) 
    1. Connect the Techstream to the DLC3.
    2. Start the engine.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Mass Air Flow Sensor and Coolant Temperature.

      Powertrain > Engine > Data List 

      Tester Display
      Engine Speed
      Mass Air Flow Sensor
      Coolant Temperature
    5. Allow the engine to idle until Coolant Temperature is 75°C (167°F) or higher.
    6. Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

      Standard

      Techstream Display Condition Specified Condition
      Mass Air Flow Sensor Engine warmed up
      Shift position: N
      A/C: Off
      Engine Speed: 3000 rpm      		 Between 7.5 and 12.5 gm/sec

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  23

    Result: 

    OK 

    See step  14

  14. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    5. Turn the engine switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  15

  15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A-00) 
    NOTE:

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    5. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    6. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    8. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    9. Input the DTC: P050A-00.
    10. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P050A-00 is output)      		 B

    Result: 

    A 

    CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [08/2020 - ] 

    Result: 

    B 

    See step  23

  16. CHECK AND REPAIR VVT SYSTEM 
    1. Check and repair the VVT system.

      HINT: 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  17. REPLACE EGR VALVE ASSEMBLY 
    1. Replace the EGR valve assembly.

      Refer to REMOVAL [08/2020 - 08/2021]

      HINT: 

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

      Refer to INITIALIZATION [08/2020 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  18. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 
    1. Replace the air cleaner filter element sub-assembly.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  19. REPAIR OR REPLACE INTAKE SYSTEM 
    1. Repair or replace the intake system.

      HINT: 

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

      Refer to INITIALIZATION [08/2020 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  20. REPAIR OR REPLACE PCV VALVE OR HOSE 
    1. Repair or replace PCV valve or hose.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  21. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    5. Turn the engine switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  22

  22. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A-00) 
    NOTE:

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    5. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    6. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    8. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    9. Input the DTC: P050A-00.
    10. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P050A-00 is output)      		 B

    Result: 

    A 

    END 

    Result: 

    B 

    See step  23

  23. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION) 
    1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

      Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [06/2018 - ]

      HINT: 

      Repair any problems.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  24

  24. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    5. Turn the engine switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  25

  25. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A-00) 
    NOTE:

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    5. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    6. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    8. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    9. Input the DTC: P050A-00.
    10. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P050A-00 is output)      		 B

    Result: 

    A 

    END 

    Result: 

    B 

    See step  26

  26. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      C18-3 (5V) - C77-78 (VCVG) Always Below 1 Ω
      C18-1 (FG) - C77-101 (VG) Always Below 1 Ω
      C18-2 (E2G) - C77-79 (E2G) Always Below 1 Ω
      C18-3 (5V) or C77-78 (VCVG) - Body ground and other terminals Always 10 kΩ or higher
      C18-1 (FG) or C77-101 (VG) - Body ground and other terminals Always 10 kΩ or higher
      C18-2 (E2G) or C77-79 (E2G) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  27

  27. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY 
    1. Replace the mass air flow meter sub-assembly.

      Refer to REMOVAL [08/2020 - ]

      HINT: 

      • If the result of the inspection performed in step 13 (READ VALUE USING TECHSTREAM (MASS AIR FLOW SENSOR)) indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
      • Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

        Refer to INITIALIZATION [08/2020 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  28

  28. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    5. Turn the engine switch off and wait for at least 30 seconds.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  29

  29. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 
    NOTE:

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    5. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    6. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    8. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    9. Input the DTC: P050A-00.
    10. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P050A-00 is output)      		 B

    Result: 

    A 

    END 

    Result: 

    B 

    REPLACE ECM. Refer to  REMOVAL [08/2020 - 08/2021] 

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