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HOMESERVICE MANUALSTOYOTA2009YARIS BASE, 4D SEDAN, AUTOMATICREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCEENGINE CONTROL SYSTEM (1NZ-FE)SFI SYSTEMVC OUTPUT CIRCUITINSPECTION PROCEDURE
2009 Toyota Yaris Base, 4D Sedan, Automatic

Inspection Procedure

2009 Toyota Yaris Base, 4D Sedan, AutomaticSECTION 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: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See  PROBLEM SYMPTOMS TABLE   ) 

      NG: Go to next step 

  2. CHECK COMMUNICATION BETWEEN TESTER AND ECM 
    1. Connect a Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester ON.
    4. 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 (See  REMOVAL   ) 

      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 (See  REMOVAL   ) 

      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: Locating J25 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 CANISTER  (See REMOVAL )

      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 REFERENCE

      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 And C20 ECM Connector Terminal
      G04828337Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE ECM (See  REMOVAL   ) 

RENDER: 1.0x

NO RELATED

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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.