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Home >> Toyota >> 2021 >> Land Cruiser Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (3 Of 7) >> SFI System >> DTC P050A: Cold Start Idle Air Control System Performance [08/2018 - 08/2019] >> Procedure
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DTC P050A: Cold Start Idle Air Control System Performance [08/2018 - 08/2019]: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following the menus: Powertrain / Engine and ECT / Trouble Codes.
    5. Read the DTCs.

      Result

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

      HINT: 

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

    Result: 

    GO TO DTC CHART 

    (Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2018 - 08/2019] )

    Result: 

    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.

    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Enter the following menus: Powertrain / Engine and ECT / Data List / Short FT B1S1 and Long FT B1S1, or Short FT B2S1 and Long FT B2S1.
    4. Read the values displayed on the Techstream.
    5. Add together the Short FT B1S1 and Long FT B1S1, or Short FT B2S1 and Long FT B2S1 values to obtain the total fuel trim.

      Result

      Total of Short FT B1S1 and Long FT B1S1, or Short FT B2S1 and Long FT B2S1 values is between -20% and 20%.

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  3

  3. INSPECT THROTTLE BODY ASSEMBLY 
    1. Check for deposits around the throttle valve and throttle valve condition.

      OK

      No deposits around throttle valve and throttle valve moves smoothly.

    Result: 

    OK 

    See step  14

    Result: 

    NG 

    See step  4

  4. REPAIR OR REPLACE THROTTLE BODY ASSEMBLY 
    1. Repair or replace the throttle body assembly (Refer to REMOVAL [08/2015 - ] ).

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the throttle body assembly (Refer to INITIALIZATION [08/2015 - ] ).

    Result: 

    NEXT 

    See step  14

  5. CHECK PCV SYSTEM 
    1. Allow the engine to idle.
    2. Pinch the positive crankcase ventilation (PCV) hose.
    3. Check the engine speed.

      OK

      The engine speed rises when the PCV hose is pinched.

    Result: 

    NG 

    See step  10

    Result: 

    OK 

    See step  6

  6. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leakage (Refer to PROCEDURE - Step 4 ).

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the air induction system (Refer to INITIALIZATION [08/2015 - ] ).

    Result: 

    NG 

    See step  11

    Result: 

    OK 

    See step  7

  7. CHECK AIR CLEANER FILTER ELEMENT SUBASSEMBLY 
    1. Visually check that the air cleaner filter element is not excessively contaminated with dirt or oil.

      OK

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

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  8

  8. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT SYSTEM) 
    1. Connect the Techstream to the DLC3.
    2. Start the engine.
    3. Turn the Techstream on.
    4. Warm up the engine.
    5. Turn the A/C on.
    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1) or Control the VVT Linear (Bank 2).
    7. Check the engine speed while operating the camshaft oil control valve using the Techstream.

      OK

      Techstream Operation Engine Condition
      0% Normal engine speed
      100% Engine idles roughly or stalls

      HINT: 

      Refer to "Data List / Active Test" [VVT OCV Duty #1, VVT Change Angle #1, VVT OCV Duty #2 and VVT Change Angle #2] (Refer to DATA LIST / ACTIVE TEST [08/2018 - 08/2019] ).

    Result: 

    NG 

    See step  13

    Result: 

    OK 

    See step  9

  9. READ VALUE USING TECHSTREAM (MAF) 
    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 and ECT / Data List / All Data / MAF and Coolant Temp.
    5. Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
    6. Read MAF with the engine speed at 3000 rpm.

      Standard

      Between 25.2 gm/sec and 35.2 gm/sec (shift lever: N; A/C: Off).

    Result: 

    OK 

    See step  14

    Result: 

    NG 

    See step  15

  10. REPAIR OR REPLACE PCV HOSE 
    1. Repair or replace the PCV hose.

    Result: 

    NEXT 

    See step  14

  11. REPAIR OR REPLACE AIR INDUCTION SYSTEM 
    1. Repair or replace the air induction system.

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the air induction system (Refer to INITIALIZATION [08/2015 - ] ).

    Result: 

    NEXT 

    See step  14

  12. REPLACE AIR CLEANER FILTER ELEMENT SUBASSEMBLY 
    1. Replace the air cleaner filter element subassembly.

    Result: 

    NEXT 

    See step  14

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

    Result: 

    NEXT 

    See step  14

  14. CHECK WHETHER DTC OUTPUT RECURS 
    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. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - ] ).
    5. Turn the engine switch off.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
    8. Check that the engine coolant temperature is between - 10°C and 50°C (14 and 122°F).
    9. Start the engine and warm it up.
    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    12. Input the DTC: P050A.
    13. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P050A is output) B

    Result: 

    CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [08/2015 - ] 

    Result: 

    See step  15

  15. CHECK HARNESS AND CONNECTOR 
    1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM (Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [08/2015 - ] ).

      HINT: 

      Repair any problems.

    Result: 

    NEXT 

    See step  16

  16. CHECK WHETHER DTC OUTPUT RECURS 
    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. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - ] ).
    5. Turn the engine switch off.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
    8. Check that the engine coolant temperature is between - 10°C and 50°C (14 and 122°F).
    9. Start the engine and warm it up.
    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    12. Input the DTC: P050A.
    13. Check the DTC judgment result.

      Result

      Result Proceed to
      ABNORMAL (DTC P050A is output) A
      NORMAL (DTC is not output) B

    Result: 

    END 

    Result: 

    See step  17

  17. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the mass air flow meter 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
      C3-3 (VG) - C53-68 (VG) Always Below 1 Ω
      C3-2 (E2G) - C53-70 (E2G) Always Below 1 Ω
      C3-3 (VG) or C53-68 (VG) - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  18

  18. REPLACE MASS AIR FLOW METER ASSEMBLY 
    1. Replace the mass air flow meter assembly (Refer to REMOVAL [08/2015 - ] ).

      HINT: 

      • If the result of the inspection performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter assembly.
      • Perform "Inspection After Repair" after replacing the mass air flow meter (Refer to INITIALIZATION [08/2015 - ] ).

    Result: 

    NEXT 

    See step  19

  19. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    HINT: 

    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. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - ] ).
    5. Turn the engine switch off.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
    8. Check that the engine coolant temperature is between - 10°C and 50°C (14 and 122°F).
    9. Start the engine and warm it up.
    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    12. Input the DTC: P050A.
    13. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P050A is output) B

    Result: 

    END 

    Result: 

    REPLACE ECM 

    (Refer to REMOVAL [08/2015 - ] )