2009 Toyota Yaris S, 4D HatchbackFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. INSPECT FUEL INJECTOR (POWER SOURCE) 
    1. Disconnect the fuel injector connectors.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connections Specified Conditions
      C4-1 - Body ground 11 to 14 V
      C5-1 - Body ground 11 to 14 V
      C6-1 - Body ground 11 to 14 V
      C7-1 - Body ground 11 to 14 V
    4. Reconnect the fuel injector connectors.

      NG: Go to step  6

      Fig 1: Identifying Fuel Injector Connector Terminal
      G05590764Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  2. INSPECT FUEL INJECTOR (INJECTOR RESISTANCE) 
    1. Disconnect the fuel injector connectors.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE REFERENCE

      Tester Connections Specified Conditions
      1 - 2 11.6 to 12.4 Ω at 20°C (68°F)
    3. Reconnect the fuel injector connectors.

      NG: REPLACE FUEL INJECTOR  (See REMOVAL )

      Fig 2: Identifying Fuel Injector Connectors
      G05590765Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM) 
    1. Disconnect the C20 ECM connector.
    2. Disconnect the fuel injector connectors.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE REFERENCE

      Tester Connections Specified Conditions
      C4-2-C20-108 (#10) Below 1 Ω
      C5-2-C20-107 (#20) Below 1 Ω
      C6-2-C20-106 (#30) Below 1 Ω
      C7-2-C20-105 (#40) Below 1 Ω

      Standard resistance (Check for short) 

      RESISTANCE REFERENCE

      Tester Connections Specified Conditions
      C4-2 or C20-108 (#10) - Body ground 10 kΩ or higher
      C5-2 or C20-107 (#20) - Body ground 10 kΩ or higher
      C6-2 or C20-106 (#30) - Body ground 10 kΩ or higher
      C7-2 or C20-105 (#40) - Body ground 10 kΩ or higher
    4. Reconnect the fuel injector connectors.
    5. Reconnect the ECM connector.

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 3: Identifying Fuel Injector Connector Terminal
      G05590766Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the C20 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE REFERENCE

      Tester Connections Specified Conditions
      C20-45 (E01) - Body ground Below 1 Ω
      C20-44 (E02) - Body ground Below 1 Ω
    3. Reconnect the ECM connector.

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 4: Identifying C20 ECM Connector Terminal
      G06131205Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  5. INSPECT FUEL INJECTOR (INJECTION AND VOLUME) 
    1. Check the fuel injector injection and volume (See INSPECTION ).

      NG: REPLACE FUEL INJECTOR  (See REMOVAL )

      OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See  PROBLEM SYMPTOMS TABLE   ) 

  6. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - INTEGRATION RELAY) 
    1. Disconnect the fuel injector connectors.
    2. Remove the integration relay from the engine room relay block.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE REFERENCE

      Tester Connections Specified Conditions
      C4-1 - 1B-4 (Integration relay) Below 1 Ω
      CS-1 - 1B-4 (Integration relay) Below 1 Ω
      C6-1 - 1B-4 (Integration relay) Below 1 Ω
      C7-1 - 1B-4 (Integration relay) Below 1 Ω

      Standard resistance (Check for short) 

      RESISTANCE REFERENCE

      Tester Connections Specified Conditions
      C4-1 or 1B-4 (Integration relay) - Body ground 10 kΩ or higher
      C5-1 or 1B-4 (Integration relay) - Body ground 10 kΩ or higher
      C6-1 or 1 B-4 (Integration relay) - Body ground 10 kΩ or higher
      C7-1 or 1 B-4 (Integration relay) - Body ground 10 kΩ or higher
    4. Reconnect the fuel injector connectors.
    5. Reinstall the integration relay.

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 5: Identifying Integration Relay And Engine Room Relay Block
      G05590768Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT (See  ECM POWER SOURCE CIRCUIT   ) 

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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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