LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2008 >> Yaris Base, 2D Hatchback, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control System (1NZ-FE) >> SFI System >> Fuel Pump Control Circuit >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

  1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED) 
    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 / Active Test / Control the Fuel Pump/Speed.
    5. Check whether the fuel pump operating sound occurs when perform the Active Test on the tester.

      OK: Fuel pump operating sound occurs. 

    OK:  Go to step  8

    NG: Go to Next Step 

  2. INSPECT MAIN BODY ECU (C/OPN RELAY INPUT VOLTAGE) 
    1. Measure the voltage between the terminal of the main body ECU and the body ground when the ignition switch is turned to ON and OFF.

      Standard voltage 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

      Tester Connections Switch Conditions Specified Conditions
      4B-11 - Body ground Ignition switch OFF Below 1 V
      4F-4 - Body ground
      4B-11 - Body ground Ignition switch ON 11 to 14 V
      4F-4 - Body ground
      Fig 1: Identifying Instrument Panel Junction Block Assembly (C/OPN Relay Input Voltage)
      G04828340Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK:  Go to step  4

    NG: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - INTEGRATION RELAY) 
    Fig 2: Identifying Harness And Connector (Main Body ECU - Integration Relay)
    G04828341Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Disconnect the main body ECU connector.
    3. Check the resistance.

      Standard resistance (Check for open) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

      Tester Connections Specified Conditions
      1B-4 - 4F-4 Below 1 Ω
      1A-4 - 4B-11

      Standard resistance (Check for short) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

      Tester Connections Specified Conditions
      4F-4 - Body ground 10 kΩ or higher
      4B-11 - Body ground
    4. Reinstall the integration relay.
    5. Reconnect the main body ECU connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK:  GO TO ECM POWER SOURCE CIRCUIT 

  4. INSPECT MAIN BODY ECU (C/OPN RELAY) 
    1. Remove the main body ECU.
    2. Check the C/OPN relay resistance.

      Standard resistance 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

      Tester Connections Specified Conditions
      4B-11 - 4A-8 10 kΩ or higher
      Below 1 Ω (when battery voltage is applied to terminals 4D-1 and 4E-5)
      Fig 3: Identifying Instrument Panel Junction Block Assembly (C/OPN Relay)
      G04828342Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      Relay coil circuit between 4D-1 and 4E-5 is not through IGN fuse.

    3. Reinstall the main body ECU.

    NG: REPLACE MAIN BODY ECU 

    OK: Go to Next Step 

  5. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM) 
    Fig 4: Identifying Harness And Connector (Instrument Panel J/B - ECM)
    G04828343Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A21 ECM connector.
    2. Disconnect the 4E connector from main body ECU.
    3. Check the resistance.

      Standard resistance (Check for open) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

      Tester Connections Specified Conditions
      Main Body ECU (4E-5) - FC (A21-7) Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

      Tester Connections Specified Conditions
      Main body ECU (4E-5) or FC (A21-7) - Body ground 10 kΩ or higher
    4. Reconnect the main body ECU and the ECM connectors.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  6. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP - BODY GROUND) 
    Fig 5: Identifying Harness And Connector (C/OPN Relay - Fuel Pump - Body Ground)
    G04828344Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Check the harness and the connectors between the main body ECU and the fuel pump.
      1. Disconnect the 4A main body ECU connector.
      2. Disconnect the J5 fuel pump connector.
      3. Check the resistance.

        Standard resistance (Check for open) 

        TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

        Tester Connections Specified Conditions
        Main body ECU (4A-8) - Fuel pump (J5-4) Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

        Tester Connections Specified Conditions
        Main body ECU (4A-8) or Fuel pump (J5-4) - Body ground 10 kΩ or higher
    2. Check the harness and the connectors between the fuel pump and the body ground.
      1. Disconnect the J5 fuel pump connector.
      2. Check the resistance.

        Standard resistance (Check for open) 

        TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

        Tester Connections Specified Conditions
        Fuel pump (J5-5) - Body ground Below 1 Ω
    3. Reconnect the main body ECU connector.
    4. Reconnect the fuel pump connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  7. INSPECT FUEL PUMP 
    1. Inspect fuel pump resistance.
      1. Measure the resistance between the terminals.

        Standard resistance: 0.2 to 3.0 Ω at 20°C (68°F) 

    2. Inspect fuel pump operation.
      Fig 6: Identifying Fuel Pump Operation
      G04828345Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Apply the battery voltage to both the terminals. Check that the pump operates.
        NOTE:
        • These tests must be done quickly (within 10 seconds) to prevent the coil from burning out.
        • Keep the fuel pump as far away from the battery as possible.
        • Always switch at the battery side.

    NG: REPLACE FUEL PUMP  (See REMOVAL )

    OK: REPLACE ECM (See  REMOVAL   ) 

  8. READ VALUE USING TECHSTREAM (STARTER SIGNAL) 
    1. Connect the 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 / All Data / Starter Signal.
    5. Check the result when the ignition switch is turned to ON and START.

      Standard 

      IGNITION SWITCH POSITIONS CHART

      Ignition Switch Position Starter Signal
      ON OFF
      START ON

    NG: REPAIR OR REPLACE STARTING SYSTEM (See  INSPECTION PROCEDURE   ) 

    OK: Go to Next Step 

  9. READ VALUE USING TECHSTREAM (ENGINE SPEED) 
    1. Connect the 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 / All Data / Engine Speed.
    5. Read the values displayed on the tester while cranking.

      Standard: Values are displayed continuously. 

    NG: REPAIR OR REPLACE CRANKSHAFT POSITION SENSOR CIRCUIT (See  INSPECTION PROCEDURE   ) 

    OK: REPLACE ECM (See  REMOVAL   ) 

scientia non olet · About LEMON Manuals