Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Toyota >> 2011 >> Yaris 2D Hatchback, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control SFI System (Diagnostic Codes (P043E-P1605) >> SFI System >> DTC P050A: Cold Start Idle Air Control System Performance >> Procedure

DTC P050A: Cold Start Idle Air Control System Performance: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
    5. Read 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   20 

    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 the Techstream to the DLC3.
    2. Start the engine.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Short FT #1 and Long FT #1.
    5. Read the values displayed on the Techstream while the engine is idling.
    6. Add together the Short FT #1 and Long FT #1 values to obtain the total Fuel Trim.

      Standard

      Total of Short FT #1 and Long FT #1 values is between -20% and 20%.

    NG → See step   5 

    OK: Go to next step 

  3. INSPECT THROTTLE BODY (THROTTLE VALVE) 
    1. Check that there are no deposits around the throttle valve.

      OK

      No deposits around the throttle valve.

    OK → See step   14 

    NG → See step   4 

  4. REPAIR OR REPLACE THROTTLE BODY 
    1. Repair or replace throttle body. Refer to REMOVAL .

    NEXT → See step   14 

  5. CHECK PCV SYSTEM 
    1. Check the PCV hose connections. Refer to ON-VEHICLE INSPECTION - Step 2 .

      OK

      PCV hose is connected correctly and is 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 - Step 2 .

      OK

      No leak 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 is not excessively contaminated with dirt or oil.

      OK

      The 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 (OPERATE OCV). Refer to  PROCEDURE - Step 2 

    NG → See step   13 

    OK: Go to next step 

  9. READ VALUE USING TECHSTREAM (MAF). Refer to  PROCEDURE - Step 6 

    OK → See step   14 

    NG → See step   15 

  10. REPAIR OR REPLACE PCV SYSTEM 
    1. Repair or replace the PCV system.

    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: 

      DTC P0011 Inspection Procedure. Refer to INSPECTION PROCEDURE

    NEXT: Go to next step 

  14. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED (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 ignition switch to ON.
    3. Turn the Techstream on.
    4. Clear DTCs. Refer to DTC CHECK / CLEAR .
    5. Turn the ignition switch off and wait for at least 30 seconds.
    6. Turn the ignition switch to ON.
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
    9. Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
    10. Start the engine and warm it up.
    11. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    13. Input the DTC: P050A.
    14. Check the DTC judgment result.
      RESULT

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

    B → See step   15 

    A → CHECK FOR INTERMITTENT PROBLEMS 

  15. 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 .

      HINT: 

      Repair any problems.

    NEXT: Go to next step 

  16. 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 a Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Clear DTCs. Refer to DTC CHECK / CLEAR .
    5. Turn the ignition switch off and wait for at least 30 seconds.
    6. Turn the ignition switch to ON.
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
    9. Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
    10. Start the engine and warm it up.
    11. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    13. Input the DTC: P050A.
    14. 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 

  17. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM). Refer to  PROCEDURE - Step 6 

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  18. REPLACE MASS AIR FLOW METER 
    1. Replace the mass air flow meter. Refer to REMOVAL .

      HINT: 

      If the results of the inspections performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter.

    NEXT: Go to next step 

  19. 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 ignition switch to ON.
    3. Turn the Techstream on.
    4. Clear DTCs. Refer to DTC CHECK / CLEAR .
    5. Turn the ignition switch off and wait for at least 30 seconds.
    6. Turn the ignition switch to ON.
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
    9. Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
    10. Start the engine and warm it up.
    11. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    13. Input the DTC: P050A.
    14. Check the DTC judgment result.
      RESULT

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

    B → REPLACE ECM 

    A → END 

  20. GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
scientia non olet · About Mike's Workshop Manuals