LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2009 >> Yaris Base, 2D Hatchback, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control System (1NZ-FE) >> SFI System >> DTC P050A Cold Start Idle Air Control System Performance >> Inspection Procedure

Inspection Procedure

HINT:

Read freeze frame data using a 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 a Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester ON.
    4. Select the following menu items:
      1. Techstream - Select: Powertrain/Engine and ECT/Trouble Codes.
    5. Read DTCs.

      Result 

      RESULT REFERENCE

      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 DTC CHART 

      OK: 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 a Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester ON.
    4. Select the following menu items: Powertrain/Engine and ECT/Data List/A/F Control System/Short FT #1 and Long FT #1.
    5. Read the values displayed on the tester.
    6. Add together the Short FT #1 and Long FT #1 values to obtain the total Fuel Trim.

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

      NG: Go to step  5

      OK: Go to next step 

  3. INSPECT 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 USING TECHSTREAM (OPERATE OCV) 
    1. Connect a Techstream to the DLC3.
    2. Start the engine.
    3. Turn the tester ON.
    4. Select the following menu items: Powertrain/Engine and ECT/Active Test/Control the VVT System (Bank 1).
    5. Check the engine speed while operating the OCV using the tester.

      Result 

      RESULT REFERENCE

      Tester Operations Specified Conditions
      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 ventilation (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 (See ON-VEHICLE INSPECTION ).

      OK: No leak 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 

    HINT:

    Refer to DTC P0011 INSPECTION PROCEDURE 

    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 a Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester ON.
    4. Clear 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 DTCs.

      OK: No DTC is output. 

      NEXT: END