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Home >> Toyota >> 2008 >> 4Runner SR5, 4.7 T, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (2UZ-FE) - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection And Installation >> Fuel Pump Control Circuit >> Inspection Procedure

Inspection Procedure

  1. CHECK FUEL PUMP OPERATION 
    1. Check if there is pressure in the fuel inlet hose.

      HINT:

      If there is fuel pressure, you will hear the sound of fuel flowing.

    OK:  Go to step  10

    NG: Go To Next Step 

  2. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE CIRCUIT OPENING RELAY) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch ON and turn the tester ON.
    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
    4. Check the relay operation when it is operated by the tester.

      Standard: 

      Operating sound can be heard from the relay. 

    OK:  Go to step  5

    NG: Go To Next Step 

  3. INSPECT CIRCUIT OPENING RELAY (Marking: C/OPN) 
    1. Remove the circuit opening relay from the engine room relay block.
    2. Measure the resistance of the circuit opening relay.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      3-5 10 kΩ or higher
      3-5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2)
    3. Reinstall the circuit opening relay.
      Fig 1: Identifying A/F Relay
      G04967794Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE CIRCUIT OPENING RELAY 

    OK: Go To Next Step 

  4. INSPECT ECM (FC VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the E8 and E6 ECM connectors.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      FC (E8-10) - E1 (E6-1) 9 to 14 V
      Fig 2: Identifying ECM Connectors
      G04968184Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ECM 

    NG: CHECK AND REPAIR HARNESS OR CONNECTOR (ECM - CIRCUIT OPENING RELAY, CIRCUIT OPENING RELAY - IGNITION SWITCH) 

  5. CHECK ECM POWER SOURCE CIRCUIT 
    1. Check ECM POWER SOURCE CIRCUIT .

    NG: REPAIR OR REPLACE 

    OK: Go To Next Step 

  6. INSPECT FUEL PUMP RELAY 
    1. Remove the fuel pump relay from the engine room relay block.
    2. Measure the resistance of the fuel pump relay.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      3-4 Below 1 Ω
      3-5 10 kΩ or higher
      3-4 10 kΩ or higher (when battery voltage is applied to terminals 1 and 2)
      3-5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2)
    3. Reinstall the fuel pump relay.
      Fig 3: Identifying Fuel Pump Relay
      G04829434Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE FUEL PUMP RELAY 

    OK: Go To Next Step 

  7. INSPECT FUEL PUMP 
    1. Check the fuel pump operation (See INSPECTION ).

    NG: REPLACE FUEL PUMP 

    OK: Go To Next Step 

  8. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP RELAY, FUEL PUMP BODY GROUND) 
    1. Check the harness and connector between the fuel pump and fuel pump relay.
      1. Disconnect the F14 fuel pump connector.
        Fig 4: Identifying F14 Fuel Pump Connector
        G04968186Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Remove the fuel pump relay from the engine room R/B.
      3. Measure the resistance between the wire harness side connectors.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Fuel pump (F14-4) - Engine room R/B (Fuel pump relay terminal 4) Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Fuel pump (F14-4) or Engine room R/B (Fuel pump relay terminal 4) - Body ground 10 kΩ or higher
    2. Check the harness and connector between the fuel pump and body ground.
      1. Disconnect the F14 fuel pump connector.
      2. Measure the resistance between the wire harness side connector and body ground.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Fuel pump (F14-5) - Body ground Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go To Next Step 

  9. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - FUEL PUMP RELAY) 
    1. Remove the circuit opening relay (C/OPN) from the engine room R/B.
    2. Remove the fuel pump relay from the engine room R/B.
    3. Measure the resistance between the wire harness side connectors.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      Circuit opening relay (3) - Engine room R/B (Fuel pump relay terminal 3) Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      Circuit opening relay (3) or Engine room R/B (Fuel pump relay terminal 3) - Body ground 10 kΩ or higher
    4. Reinstall the circuit opening relay.
    5. Reinstall the fuel pump relay.
      6. Fig 5: Identifying Circuit Opening Relay & Fuel Pump Relay
      G05553507Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: CHECK AND REPAIR HARNESS OR CONNECTOR (EFI RELAY - CIRCUIT OPENING RELAY) 

  10. INSPECT FUEL PUMP RELAY 
    1. Remove the fuel pump relay from the engine room relay block.
    2. Measure the resistance of the fuel pump relay.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      3-4 Below 1 Ω
      3-5 10 kΩ or higher
      3-4 10 kΩ or higher (when battery voltage is applied to terminals 1 and 2)
      3-5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2)
    3. Reinstall the fuel pump relay.
      Fig 6: Identifying Fuel Pump Relay
      G04829434Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE FUEL PUMP RELAY 

    OK: Go To Next Step 

  11. INSPECT FUEL PUMP RESISTOR (RESISTANCE) 
    1. Inspect the fuel pump resistor resistance.
      1. Measure the resistance of the terminals.

        Standard resistance: 

        0.70 to 0.76 Ω at 20°C (68°F) 

        Fig 7: Measuring Resistance Between Fuel Pump Resistor Terminals
        G04968189Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE FUEL PUMP RESISTOR 

    OK: Go To Next Step 

  12. CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY - FUEL PUMP RESISTOR, FUEL PUMP RESISTOR - FUEL PUMP) 
    1. Check the harness and connector between the fuel pump relay and fuel pump resistor.
      1. Remove the fuel pump relay from the engine room R/B.
      2. Disconnect the F8 fuel pump resistor connector.
      3. Check the resistance between the wire harness side connectors.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Engine room R/B (Fuel pump relay terminal 5) - Fuel pump resistor (F8-1) Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Engine room R/B (Fuel pump relay terminal 5) or Fuel pump resistor (F8-1) - Body ground 10 kΩ or higher
      4. Reinstall the fuel pump relay.
      5. Reconnect the fuel pump resistor connector.
        Fig 8: Identifying Air Conditioning Harness Assembly Interlock
        G05553510Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the harness and connector between the fuel pump resistor and fuel pump.
      1. Disconnect the F8 fuel pump resistor connector.
      2. Disconnect the F14 fuel pump connector.
      3. Check the resistance between the wire harness side connectors.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Fuel pump resistor (F8-2) - Fuel pump (F14-4) Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Tester Connection Specified Condition
        Fuel pump resistor (F8-2) or Fuel pump (F14-4) -Body ground 10 kΩ or higher
    3. Reconnect the fuel pump resistor connector.
    4. Reconnect the fuel pump connector.

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

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

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