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Home >> Lexus >> 2017 >> LS 460 Base, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (P1340-P11ED) & Circuit Tests >> SFI System >> DTC P050A: Cold Start Idle Air Control System Performance; DTC P050B: Cold Start Ignition Timing Performance [09/2016 - ] >> Procedure
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DTC P050A: Cold Start Idle Air Control System Performance; DTC P050B: Cold Start Ignition Timing Performance [09/2016 - ]: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A AND/OR P050B) 
    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 / Trouble Codes.
    5. Read the DTCs.

      Result

      Display (DTC Output) Proceed to
      P050A and/or P050B A
      P050A and/or P050B and other DTCs B

      HINT: 

      If any DTCs other than P050A and P050B are output, troubleshoot those DTCs first.

    Result:  B

    B 

    GO TO DTC CHART 

    (Refer to DIAGNOSTIC TROUBLE CODE CHART [09/2016 - ] )

    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.

    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Start the engine.
    5. Enter the following menus: Powertrain / Engine / Data List / A/F Control System / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
    6. Read the values displayed on the Techstream.
    7. Add together the Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values to obtain the total Fuel Trim.

      OK

      Total of Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values is between -20% and 20%.

    Result:  OK

    OK 

    See step  14

    Result:  NG

    NG 

    See step  3

  3. PERFORM ACTIVE TEST USING TECHSTREAM (VVT-iE SYSTEM) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Start the engine and warm it up.
    4. Engine is idling.
    5. Enter the following menus: Powertrain / Engine / Active Test / Control the VVT-iE Linear (Bank1) or Control the VVT-iE Linear (Bank2) / All Data / VVT-iE Aim Angle #1 and VVT Change Angle #1 or VVT-iE Aim Angle #2 and VVT Change Angle #2.
    6. Perform the Active Test operation with the engine speed at 1500 rpm.

      OK

      Active Test Movement Order Difference between "VVT-iE Aim Angle" and "VVT Change Angle"
      0 deg → 10 deg → 20 deg → 40 deg → 10 deg → 0 deg → 10 deg → END Within 4 DegFR

    Result:  NG

    NG 

    See step  10

    Result:  OK

    OK 

    See step  4

  4. CHECK VENTILATION HOSE CONNECTIONS 

    OK

    Ventilation hose is connected correctly and is not damaged.

    Result:  NG

    NG 

    See step  11

    Result:  OK

    OK 

    See step  5

  5. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leakage.

      OK

      No leakage from air induction system.

    Result:  NG

    NG 

    See step  12

    Result:  OK

    OK 

    See step  6

  6. 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

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

    Result:  NG

    NG 

    See step  13

    Result:  OK

    OK 

    See step  7

  7. READ VALUE USING TECHSTREAM (MAF SENSOR 1 AND MAF SENSOR 2) 
    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 / Primary / Engine Speed, Coolant Temp, MAF Sensor 1 and MAF Sensor 2.
    5. Allow the engine to idle until the ECT reaches 75°C (167°F) or higher.
    6. Read MAF Sensor 1 and MAF Sensor 2 with the engine speed at 2000 rpm.

      Standard

      Between 2.4 to 12.8 g/s (shift lever is in N position and A/C is OFF)

    Result:  OK

    OK 

    CHECK FOR INTERMITTENT PROBLEMS 

    (Refer to CHECK FOR INTERMITTENT PROBLEMS [09/2015 - ] )

    Result:  NG

    NG 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    GTY664387Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the E13 or E22 MAF meter connector.
    2. Disconnect the E1 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open)

      Tester Connection Condition Specified Condition
      E13-1 (VG) - E1-25 (VG) Always Below 1 Ω
      E13-2 (E2G) - E1-24 (E2G) Always Below 1 Ω
      E22-1 (VGR) - E1-23 (VG2) Always Below 1 Ω
      E22-2 (EVGR) - E1-32 (E2G2) Always Below 1 Ω

      Standard resistance (Check for short)

      Tester Connection Condition Specified Condition
      E13-1 (VG) or E1-25 (VG) - Body ground Always 10 kΩ or higher
      E22-1 (VGR) or E1-23 (VG2) - Body ground Always 10 kΩ or higher

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  9

  9. REPLACE MASS AIR FLOW METER (BANK 1 AND/OR BANK 2) 
    1. Replace the mass air flow meter (Refer to REMOVAL [09/2015 - ] ).

      HINT: 

      Perform "Inspection After Repair" after replacing the mass air flow meter (Refer to INITIALIZATION [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  17

  10. CHECK AND REPAIR VVT-iE SYSTEM 
    1. Check and repair the VVT-iE system (Refer to DISASSEMBLY [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  17

  11. REPAIR OR REPLACE VENTILATION HOSE 
    1. Repair or replace the ventilation hose (Refer to ON-VEHICLE INSPECTION [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  17

  12. REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    HINT: 

    Perform "Inspection After Repair" after repairing or replacing the air induction system (Refer to INITIALIZATION [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  17

  13. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 

    Result:  NEXT

    NEXT 

    See step  17

  14. CHECK 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  16

    Result:  OK

    OK 

    See step  15

  15. REPLACE ECM 
    1. Replace the ECM (Refer to REMOVAL [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  17

  16. REPAIR OR REPLACE THROTTLE BODY 
    1. Repair or replace the throttle body (Refer to REMOVAL [09/2015 - ] ).

      HINT: 

      Perform "Inspection After Repair" after replacing the throttle body (Refer to INITIALIZATION [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  17

  17. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B) 
    NOTE:

    In this operation, the engine must be cold (the same level 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 DTCs (Refer to DTC CHECK / CLEAR [09/2015 - ] ).
    5. Switch the ECM from normal mode to check mode using the Techstream (Refer to CHECK MODE PROCEDURE [09/2015 - ] ).
    6. Start the engine to idle for a minute.

      OK

      Stable fast idling.

    7. Read DTCs.

      OK

      No DTC output.

    Result:  NEXT

    NEXT 

    END 

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