2007 Toyota Yaris S, AutomaticFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. CHECK MIL 
    1. Check that Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch ON.

      OK: MIL lights up 

    OK: SYSTEM OK 

    NG: GO TO NEXT STEP 

  2. CHECK COMMUNICATION BETWEEN INTELLIGENT TESTER AND ECM 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch to ON and tester ON.
    3. Check the communication between the tester and ECM.

      Result 

      RESULT REFERENCE

      Result Proceed To
      Communication is possible A
      Communication is not possible B

    A: GO TO  MIL CIRCUIT  

    B: GO TO NEXT STEP 

  3. CHECK MIL (THROTTLE POSITION SENSOR) 
    1. Disconnect the C17 throttle body connector.
    2. Turn the ignition switch to ON.
    3. Check the MIL.

      Result 

      RESULT REFERENCE

      Result Proceed To
      MIL Illuminates A
      MIL does not illuminate B
    4. Reconnect the throttle body connector.

    A: REPLACE THROTTLE BODY ASSEMBLY 

    B: GO TO NEXT STEP 

  4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR) 
    1. Disconnect the A20 accelerator pedal position sensor connector.
    2. Turn the ignition switch to ON.
    3. Check the MIL.

      Result 

      RESULT REFERENCE

      Result Proceed To
      MIL Illuminates A
      MIL does not illuminate B
    4. Reconnect the accelerator pedal position sensor connector.

    A: REPLACE ACCELERATOR PEDAL POSITION SENSOR 

    B: GO TO NEXT STEP 

  5. CHECK MIL (CANISTER PUMP MODULE) 
    1. Disconnect the J25 canister pump module connector.
    2. Turn the ignition switch to ON.
    3. Check the MIL.
      Fig 1: Identifying Canister Pump Module Connector
      G04828336Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      RESULT REFERENCE

      Result Proceed to
      MIL Illuminates A
      MIL does not illuminate B
    4. Reconnect the canister pump module connector.

    A: REPLACE CHARCOAL CANISTER ASSEMBLY 

    B: GO TO NEXT STEP 

  6. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the C17 throttle body connector.
    2. Disconnect the A20 accelerator pedal position sensor connector.
    3. Disconnect the J25 canister pump module connector.
    4. Disconnect the A21 and C20 ECM connectors.
    5. Check the resistance.

      Standard resistance (Check for short) 

      RESISTANCE SPECIFICATION

      Tester Connections Specified Conditions
      VCTA (C20-67) - Body ground 10 kΩ or higher
      VCPA (A21-57) - Body ground
      VCP2 (A21-58) - Body ground
      VCPP (C20-70) - Body ground
    6. Reconnect the throttle body connector.
    7. Reconnect the accelerator pedal position sensor connector.
    8. Reconnect the canister pump module connector.
    9. Reconnect the ECM connectors.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying A21 & C20 ECM Connectors
    G04828337Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ECM 

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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