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Home >> Toyota >> 2007 >> Tundra Base, 4.0 U >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (1GR-FE) - DTC P0500 - P0657 >> DTC P050A Cold Start Idle Air Control System Performance >> Inspection Procedure

Inspection Procedure

HINT:

Read freeze frame data using the intelligent tester or Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A) 
    1. Connect the intelligent tester or Techstream to the DLC3.
    2. Turn the ignition switch ON.
    3. Turn the tester ON.
    4. Enter the following menus:
      1. Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
      2. Techstream - Select: Powertrain / Engine and ECT / Trouble Codes.
    5. Read the DTCs.

      Result 

      ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)

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

      HINT:

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

    NG: Go TO  DIAGNOSTIC TROUBLE CODE CHART 

    OK: Go to next step 

  2. READ VALUE OF INTELLIGENT TESTER (FUEL TRIM) 

    HINT:

    Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.

    1. Connect the intelligent tester or Techstream to the DLC3.
    2. Turn the ignition switch ON.
    3. Turn the tester ON.
    4. Enter the following menus:
      1. Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / DATA LIST / A/F CONTROL SYS / SHORT FT #1 and LONG FT #1, or SHORT FT #2 and LONG FT #2.
      2. Techstream - Select: Powertrain / Engine and ECT / Data List / A/F Control System / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
    5. Read the values displayed on the tester.
    6. Add together the SHORT FT #1 (Short FT #1) and LONG FT #1 (Long FT #1), or SHORT FT #2 (Short FT #2) and LONG FT #2 (Long FT #2) values to obtain the total Fuel Trim

      OK: Total of SHORT FT #1 (Short FT #1) and LONG FT #1 (Long FT #1), or SHORT FT #2 (Short FT #2) and LONG FT #2 (Long FT #2) values is between -20% and 20%. 

    NG:  Go to step  5

    OK: Go to next step 

  3. CHECK THROTTLE BODY 
    1. Check that there are no deposits around the throttle valve.

      OK: No deposits around the throttle valve 

    NG:  Go to step  10

    OK: Go to next step 

  4. REPLACE ECM 
    1. Replace ECM (see REMOVAL ).

    NEXT:  Go to step  15

  5. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE OCV) 
    1. Connect the intelligent tester or Techstream to the DLC3.
    2. Start the engine and turn the tester ON.
    3. Warm up the engine.
    4. Enter the following menus:
      1. Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / VVT CTRL B1 or VVT CTRL B2.
      2. Techstream - Select: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1) or Control the VVT System (Bank 2).
    5. Check the engine speed while operating the Oil Control Valve (OCV) using the tester.

      OK 

      OPERATE OCV

      Tester Operation Specified Condition
      OCV OFF Normal engine speed
      OCV ON Engine idles roughly or stalls (soon after OCV switched from OFF to ON)

    NG:  Go to step  11

    OK: Go to next step 

  6. CHECK PCV SYSTEM 
    1. Start the engine.
    2. Pinch the positive crankcase PCV hose.
    3. Check the engine rpm.

      OK: The engine rpm rises when the PCV hose is pinched. 

    NG:  Go to step  12

    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:  Go to step  13

    OK: Go to next step 

  8. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leaks.

      OK: No leakage from the air induction system. 

    NG:  Go to step  14

    OK: Go to next step 

  9. REPLACE MASS AIR FLOW METER 
    1. Replace mass air flow meter (see REMOVAL ).

    NEXT:  Go to step  15

  10. REPAIR OR REPLACE THROTTLE BODY 
    1. Repair or replace throttle body (see REMOVAL ).

    NEXT:  Go to step  15

  11. CHECK AND REPAIR VVT SYSTEM 

    NEXT:  Go to step  15

  12. REPAIR OR REPLACE PCV SYSTEM 

    NEXT:  Go to step  15

  13. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 

    NEXT:  Go to step  15

  14. REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    NEXT: Go to step 15 

  15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A) 
    NOTE: For this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
    1. Connect the intelligent tester or Techstream to the DLC3.
    2. Turn the ignition switch ON.
    3. Turn the tester ON.
    4. Clear the DTCs (see DTC CHECK / CLEAR ).
    5. Switch the ECM from normal mode to check mode using the tester (see CHECK MODE PROCEDURE ).
    6. Start the engine and idle it for one minute.

      OK: Stable fast idle 

    7. Read the DTCs.

      OK: No DTC is output. 

    NEXT: END 

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