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Home >> Lexus >> 2017 >> CT 200h Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (2 Of 3) >> SFI System >> DTC P050A: Cold Start Idle Air Control System Performance [08/2014 - ] >> Procedure

DTC P050A: Cold Start Idle Air Control System Performance [08/2014 - ]: 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.

    Result:  B

    B 

    GO TO DTC CHART 

    (See article. Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2014 - 08/2015] Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2015 - 06/2016] Refer to DIAGNOSTIC TROUBLE CODE CHART [06/2016 - ] )

    Result:  A

    A 

    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 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) (See article. Refer to INSPECTION MODE PROCEDURE [08/2014 - ] ).
    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%.

    Result:  NG

    NG 

    See step  7

    Result:  OK

    OK 

    See step  3

  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.

    Result:  NG

    NG 

    See step  6

    Result:  OK

    OK 

    See step  4

  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) (See article. Refer to INSPECTION MODE PROCEDURE [08/2014 - ] ).
    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. Confirm that the Throttle Idle Position is ON and check the 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 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
      MAP
      (Data List)      		 (EGR valve is fully closed) MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      HINT: 

      • While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
      RESULT

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

    Result:  B

    B 

    See step  19

    Result:  A

    A 

    See step  5

  5. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly (See article. Refer to REMOVAL [08/2014 - ] ).
    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

    Result:  OK

    OK 

    See step  19

    Result:  NG

    NG 

    See step  17

  6. REPAIR OR REPLACE THROTTLE BODY ASSEMBLY 
    1. Repair or replace the throttle body assembly (See article. Refer to REMOVAL [08/2014 - ] ).

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the throttle body assembly (See article. Refer to INITIALIZATION [08/2014 - ] ).

    Result:  NEXT

    NEXT 

    See step  19

  7. CHECK PCV SYSTEM 
    1. Check the PCV hose connections (See article. Refer to COMPONENTS [08/2014 - ] ).

      OK

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

    Result:  NG

    NG 

    See step  14

    Result:  OK

    OK 

    See step  8

  8. CHECK INTAKE SYSTEM 
    1. Check the intake system for vacuum leaks (See article. Refer to ON-VEHICLE INSPECTION [08/2014 - ] ).

      OK

      No leaks in intake system.

    Result:  NG

    NG 

    See step  15

    Result:  OK

    OK 

    See step  9

  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.

    Result:  NG

    NG 

    See step  16

    Result:  OK

    OK 

    See step  10

  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) (See article. Refer to INSPECTION MODE PROCEDURE [08/2014 - ] ).
    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. Confirm that the Throttle Idle Position is ON and check the 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 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
      MAP
      (Data List)      		 (EGR valve is fully closed) MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      HINT: 

      • While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
      RESULT

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

    Result:  B

    B 

    See step  12

    Result:  A

    A 

    See step  11

  11. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly (See article. Refer to REMOVAL [08/2014 - ] ).
    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

    Result:  NG

    NG 

    See step  17

    Result:  OK

    OK 

    See step  12

  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) (See article. Refer to PROCEDURE - Step 2 ).

    Result:  NG

    NG 

    See step  18

    Result:  OK

    OK 

    See step  13

  13. READ VALUE USING TECHSTREAM (MAF) 

    Refer to PROCEDURE - Step 6

    Result:  OK

    OK 

    See step  19

    Result:  NG

    NG 

    See step  20

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

    Result:  NEXT

    NEXT 

    See step  19

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

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the intake system (See article. Refer to INITIALIZATION [08/2014 - ] ).

    Result:  NEXT

    NEXT 

    See step  19

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

    Result:  NEXT

    NEXT 

    See step  19

  17. REPLACE EGR VALVE ASSEMBLY 
    1. Replace the EGR valve assembly (See article. Refer to REMOVAL [08/2014 - ] ).

      HINT: 

      Perform "Inspection After Repair" after replacing the EGR valve assembly (See article. Refer to INITIALIZATION [08/2014 - ] ).

    Result:  NEXT

    NEXT 

    See step  19

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

      HINT: 

    Result:  NEXT

    NEXT 

    See step  19

  19. 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 (See article. Refer to DTC CHECK / CLEAR [08/2014 - ] ).
    5. Turn the power switch off and wait for at least 30 seconds.
    6. Turn the power switch on (IG).
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.
    9. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    10. Put the engine in inspection mode (maintenance mode) (See article. Refer to INSPECTION MODE PROCEDURE [08/2014 - ] ).
    11. 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.
    12. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    14. Input the DTC: P050A.
    15. Check the DTC judgment result.
      RESULT

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

    Result:  A

    A 

    END 

    Result:  B

    B 

    See step  20

  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 (See article. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [08/2014 - ] ).

      HINT: 

      Repair any problems.

    Result:  NEXT

    NEXT 

    See step  21

  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 (See article. Refer to DTC CHECK / CLEAR [08/2014 - ] ).
    5. Turn the power switch off and wait for at least 30 seconds.
    6. Turn the power switch on (IG).
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.
    9. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    10. Put the engine in inspection mode (maintenance mode) (See article. Refer to INSPECTION MODE PROCEDURE [08/2014 - ] ).
    11. 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.
    12. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    14. Input the DTC: P050A.
    15. Check the DTC judgment result.
      RESULT

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

    Result:  B

    B 

    END 

    Result:  A

    A 

    See step  22

  22. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

    Refer to PROCEDURE - Step 3

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  23

  23. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY 
    1. Replace the mass air flow meter sub-assembly (See article. Refer to REMOVAL [08/2014 - ] ).

      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.
      • Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly (See article. Refer to INITIALIZATION [08/2014 - ] ).

    Result:  NEXT

    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. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs (See article. Refer to DTC CHECK / CLEAR [08/2014 - ] ).
    5. Turn the power switch off and wait for at least 30 seconds.
    6. Turn the power switch on (IG).
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.
    9. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
    10. Put the engine in inspection mode (maintenance mode) (See article. Refer to INSPECTION MODE PROCEDURE [08/2014 - ] ).
    11. 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.
    12. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    14. Input the DTC: P050A.
    15. Check the DTC judgment result.
      RESULT

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

    Result:  A

    A 

    END 

    Result:  B

    B 

    REPLACE ECM 

    (See article. Refer to REMOVAL [08/2014 - ] )

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