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Home >> Lexus >> 2013 >> IS 250C Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P0190-P0630)) >> SFI System >> DTC P050A: Cold Start Idle Air Control System Performance >> Procedure
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DTC P050A: Cold Start Idle Air Control System Performance: Procedure

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

    B → See step   22 

    A: Go to next step 

  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 Techstream to the DLC3.
    2. Start the engine warm it up.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / All Data / Short FT #1, Long FT #1, Short FT #2 and Long FT #2.
    5. Read the values displayed on the Techstream at the engine is idle.
    6. Add together the Short FT #1 and Long FT #1 values, and the Short FT #2 and Long FT #2 values to obtain the total fuel trim.

      OK

      The total of the Short FT #1 and Long FT #1 values, and the total of the Short FT #2 and Long FT #2 values is between -20% and 20%.

    NG → See step   5 

    OK: Go to next step 

  3. INSPECT THROTTLE BODY ASSEMBLY (THROTTLE VALVE) 
    1. Inspect that there are no deposits around the throttle valve and check the throttle valve condition.

      OK

      No deposits around the throttle valve and throttle valve moves smoothly.

      Result

      Result Proceed to
      NG A
      OK B

    B → See step   15 

    A: Go to next step 

  4. REPAIR OR REPLACE THROTTLE BODY ASSEMBLY 
    1. Repair or replace the throttle body assembly. Refer to REMOVAL [08/2012 - ] .

    NEXT → See step   14 

  5. CHECK PCV SYSTEM 
    1. Check the PCV hose connections. Refer to ON-VEHICLE INSPECTION [08/2012 - ] - Step 2 .

      OK

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

    NG → See step   10 

    OK: Go to next step 

  6. CHECK INTAKE SYSTEM 
    1. Check the intake system for vacuum leaks. Refer to ON-VEHICLE INSPECTION [08/2012 - ] .

      OK

      No leakage from the intake system.

    NG → See step   11 

    OK: Go to next step 

  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

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

    NG → See step   12 

    OK: Go to next step 

  8. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR) 
    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 Inspection Procedure (VVT system for intake camshaft). Refer to PROCEDURE - Step 2 .
      2. Perform the Active Test, referring to DTC P0014 Inspection Procedure (VVT system for exhaust camshaft). Refer to PROCEDURE - Step 2 .

    NG → See step   13 

    OK: Go to next step 

  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 / 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 7.60 gm/s. and 11.40 gm/s. (shift lever: N position; A/C: Off).

    OK → See step   15 

    NG → See step   16 

  10. REPAIR OR REPLACE PCV HOSE 
    1. Repair or replace the PCV valve or hose. Refer to REMOVAL [08/2012 - ] .

    NEXT → See step   14 

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

    NEXT → See step   14 

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

    NEXT → See step   14 

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

      HINT: 

      • Refer to DTC P0011 Inspection Procedure (VVT system for intake camshaft). Refer to INSPECTION PROCEDURE .
      • Refer to DTC P0014 Inspection Procedure (VVT system for exhaust camshaft). Refer to INSPECTION PROCEDURE .

    NEXT: Go to next step 

  14. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A) 
    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 [08/2012 - ] .
    5. Turn the engine switch off and wait for at least 30 seconds.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
    8. Check that the engine coolant temperature is between -10 and 60°C (14 and 140°F)
    9. 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.
    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine / 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

    B → See step   16 

    A → END 

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

    In this operation, the engine must be cold (approximately the same level as the engine coolant temperature recorded in the freeze frame data).

    1. Connect 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 [08/2012 - ] .
    5. Turn the engine switch off and wait for at least 30 seconds.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
    8. Check that the engine coolant temperature is between -10 and 60°C (14 and 140°F).
    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in freeze frame data.
    10. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine / 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

    B → See step   16 

    A → See step   23 

  16. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION) 
    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 [08/2012 - ] .

      HINT: 

      Repair any problems.

    NEXT: Go to next step 

  17. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A) 
    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 [08/2012 - ] .
    5. Turn the engine switch off and wait for at least 30 seconds.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
    8. Check that the engine coolant temperature is between -10 and 60°C (14 and 140°F).
    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in freeze frame data.
    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine / 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

    B → END 

    A: Go to next step 

  18. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM). Refer to  PROCEDURE - Step 3 

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  19. REPLACE MASS AIR FLOW METER 
    1. Replace the mass air flow meter. Refer to REMOVAL [08/2012 - ] .

      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.

    NEXT: Go to next step 

  20. 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. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2012 - ] .
    5. Turn the engine switch off and wait for at least 30 seconds.
    6. Turn the engine switch on (IG) and turn the Techstream on.
    7. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
    8. Check that the engine coolant temperature is between -10 and 60°C (14 and 140°F).
    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in freeze frame data.
    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    11. Enter the following menus: Powertrain / Engine / 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

    B → See step   21 

    A → END 

  21. REPLACE ECM. Refer to  REMOVAL [08/2012 - ] 
  22. GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2012 - ] 
  23. CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [08/2012 - ] 
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