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Home >> Lexus >> 2022 >> NX 350 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (P0460-P0604) >> SFI System >> DTC P050A-00: Cold Start Idle Control System Performance [11/2021 - 03/2023] >> Procedure
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DTC P050A-00: Cold Start Idle Control System Performance [11/2021 - 03/2023]: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A-00) 
    1. 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 [11/2021 - 03/2023] 

    Result: 

    A 

    See step  2

  2. READ VALUE USING GTS (FUEL TRIM) 

    HINT: 

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

    1. Start the engine.
    2. Read the values displayed on the GTS at engine idle.

      Powertrain > Engine > Data List 

      Tester Display
      Short FT B1S1
      Long FT B1S1
    3. Add the Short FT B1S1 and Long FT B1S1 values to obtain the total fuel trim.

      Standard

      GTS 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  5

    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: 

    OK 

    See step  10

    Result: 

    NG 

    See step  4

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

      Refer to REMOVAL [11/2021 - ]

      HINT: 

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

      Refer to INITIALIZATION [11/2021 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  16

  5. CHECK PCV VALVE AND HOSE CONNECTIONS 
    GTY1077517Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Check the PCV hose connections.
    2. Check the PCV valve.

      Refer to INSPECTION [11/2021 - ]

      OK

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

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  15

    Result: 

    OK 

    See step  6

  6. 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  14

    Result: 

    OK 

    See step  7

  7. 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  13

    Result: 

    OK 

    See step  8

  8. PERFORM ACTIVE TEST USING GTS (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-i system for intake camshaft).

        Refer to DTC P0011-00: Camshaft Position "A" - Timing Over-Advanced or System Performance Bank 1; DTC P0012-00: Camshaft Position "A" - Timing Over-Retarded Bank 1 [11/2021 - 03/2023]

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

        Refer to PROCEDURE - Step 2

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  9

  9. READ VALUE USING GTS (MASS AIR FLOW SENSOR) 
    1. Start the engine.
    2. Allow the engine to idle until Coolant Temperature is 75°C (167°F) or higher.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    3. Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

      Powertrain > Engine > Data List 

      Tester Display
      Engine Speed
      Mass Air Flow Sensor

      Standard

      GTS Display Condition Specified Condition
      Mass Air Flow Sensor Engine warmed up
      Shift position: P
      A/C: Off
      Engine Speed: 3000 rpm      		 Between 5 and 15 gm/sec

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  18

    Result: 

    OK 

    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 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. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    2. 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.
    3. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    4. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    5. Input the DTC: P050A-00.

      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 [11/2021 - ] 

    Result: 

    B 

    See step  18

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

      HINT: 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  16

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

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  16

  14. 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 [11/2021 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  16

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

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  16

  16. 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  17

  17. 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. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    2. 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.
    3. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    4. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    5. Input the DTC: P050A-00.

      Result

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

    Result: 

    A 

    END 

    Result: 

    B 

    See step  18

  18. 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 [11/2021 - ]

      HINT: 

      Repair any problems.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  19

  19. 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  20

  20. 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. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    2. 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.
    3. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    4. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    5. Input the DTC: P050A-00.

      Result

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

    Result: 

    A 

    END 

    Result: 

    B 

    See step  21

  21. 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
      B20-3 (VCC) - B49-73 (VCVG) Always Below 1 Ω
      B20-1 (FG) - B49-75 (VG) Always Below 1 Ω
      B20-2 (E2G) - B49-74 (E2G) Always Below 1 Ω
      B20-3 (VCC) or B49-73 (VCVG) - Body ground and other terminals Always 10 kΩ or higher
      B20-1 (FG) or B49-75 (VG) - Body ground and other terminals Always 10 kΩ or higher
      B20-2 (E2G) or B49-74 (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  22

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

      Refer to INSPECTION [11/2021 - ]

      HINT: 

      • If the result of the inspection performed in step 9 (READ VALUE USING GTS (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 [11/2021 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  23

  23. 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  24

  24. 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. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    2. 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.
    3. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    4. Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    5. Input the DTC: P050A-00.

      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 [11/2021 - ] 

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