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Home >> Lexus >> 2013 >> CT 200h Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P0300-P0657)) >> 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 the Techstream to the DLC3.
    2. Turn the power 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.

    B → See step   25 

    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 sub-assembly.

    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG) and turn the Techstream on.
    3. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE [08/2012 - ] .
    4. Start the engine.
    5. Enter the following menus: Powertrain / Engine and ECT / Data List / Gas AF Control / Short FT #1 and Long FT #1.
    6. Read the values displayed on the Techstream.
    7. 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   7 

    OK: Go to next step 

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

      OK

      No deposits around throttle valve and throttle valve moves smoothly.

    NG → See step   6 

    OK: Go to next step 

  4. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE [08/2012 - ] .
    5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      HINT: 

      The A/C switch and all accessory switches should be off.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / Throttle Idle Position and MAP.
    7. Check that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.

      HINT: 

      • Do not leave the EGR valve open for 10 seconds or more during Active Test.
      • Be sure to return the EGR valve to step 0 when Active Test is completed.
      • Do not open the EGR valve 30 steps or more during the Active Test.

      OK

      MAP and idling condition change in response to EGR step position when Throttle Idle Position is ON in Data List.

      Standard

      - 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
      MAP
      (Data List)      		 MAP value is 20 to 40 kPa (150 to 300 mmHg)
      (EGR valve is fully closed)      		 MAP value is at least +10 kPa (75 mmHg) 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 EGR valve.

      RESULT

      Result Proceed to
      Outside of standard range A
      Within standard range B

    B → See step   19 

    A: Go to next step 

  5. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly. Refer to REMOVAL [08/2012 - ] .
    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

    OK → See step   19 

    NG → See step   17 

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

    NEXT → See step   19 

  7. CHECK PCV SYSTEM 
    1. Check the PCV hose connections. Refer to COMPONENTS [08/2012 - ] .

      OK

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

    NG → See step   14 

    OK: Go to next step 

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

      OK

      No leaks in intake system.

    NG → See step   15 

    OK: Go to next step 

  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 is not excessively contaminated with dirt or oil.

    NG → See step   16 

    OK: Go to next step 

  10. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE [08/2012 - ] .
    5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      HINT: 

      The A/C switch and all accessory switches should be off.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / Throttle Idle Position and MAP.
    7. Check that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.

      HINT: 

      • Do not leave the EGR valve open for 10 seconds or more during Active Test.
      • Be sure to return the EGR valve to step 0 when Active Test is completed.
      • Do not open the EGR valve 30 steps or more during the Active Test.

      OK

      MAP and idling condition change in response to EGR step position when Throttle Idle Position is ON in Data List.

      Standard

      - 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
      MAP
      (Data List)      		 MAP value is 20 to 40 kPa (150 to 300 mmHg)
      (EGR valve is fully closed)      		 MAP value is at least +10 kPa (75 mmHg) 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 EGR valve.

      RESULT

      Result Proceed to
      Outside of standard range A
      Within standard range B

    B → See step   12 

    A: Go to next step 

  11. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly. Refer to REMOVAL [08/2012 - ] .
    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

    NG → See step   17 

    OK: Go to next step 

  12. 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 .

    NG → See step   18 

    OK: Go to next step 

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

    OK → See step   19 

    NG → See step   20 

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

    NEXT → See step   19 

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

    NEXT → See step   19 

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

    NEXT → See step   19 

  17. REPLACE EGR VALVE ASSEMBLY 
    1. Replace the EGR valve assembly. Refer to REMOVAL [08/2012 - ] .

    NEXT → See step   19 

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

      HINT: 

    NEXT: Go to next step 

  19. 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 the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2012 - ] .
    5. Turn the power switch off and wait for at least 30 seconds.
    6. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    7. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    8. Input the DTC: P050A.
    9. Check the DTC judgment result.
      RESULT

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

    B → See step   20 

    A → END 

  20. 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 [08/2012 - ] .

      HINT: 

      Repair any problems.

    NEXT: Go to next step 

  21. 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 power switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2012 - ] .
    5. Turn the power switch off and wait for at least 30 seconds.
    6. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    7. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    8. 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 

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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  23. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY 
    1. Replace the mass air flow meter sub-assembly. Refer to REMOVAL [08/2012 - ] .

      HINT: 

      If the result of the inspection performed in step 13 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.

    NEXT: Go to next step 

  24. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 
    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 the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2012 - ] .
    5. Turn the power switch off and wait for at least 30 seconds.
    6. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    7. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    8. Input the DTC: P050A.
    9. Check the DTC judgment result.
      RESULT

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

    B → See step   26 

    A → END 

  25. GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2012 - ] 
  26. REPLACE ECM. Refer to  REMOVAL [08/2012 - ] 
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