LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> GX 470 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection, Installation >> Fuel Pump Control Circuit >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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 BY INTELLIGENT TESTER (OPERATE CIRCUIT OPENING RELAY) 
    1. Connect the intelligent tester to the DLC3 with CAN VIM.
    2. Turn the ignition switch ON and turn the intelligent tester ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP / SPD.
    4. Check the relay operation when it is operated by the intelligent 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) 
    Fig 1: Identifying Opening Relay Terminals
    G04967794Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    1. Remove the circuit opening relay from the engine room R/B.
    2. Measure the resistance of the circuit opening relay.

      Standard resistance 

      RESISTANCE SPECIFICATION

      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.

    NG: REPLACE CIRCUIT OPENING RELAY 

    OK: Go to next step 

  4. INSPECT ECM (FC VOLTAGE) 
    Fig 2: Identifying ECM Connector Terminals
    G05264283Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    1. Turn the ignition switch ON.
    2. Measure the voltage of the E7 and E9 ECM connectors.

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      FC (E9-10) - E1 (E7-1) 9 to 14 V

    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 
    Fig 3: Identifying Fuel Pump Relay Terminals
    G04829434Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    1. Remove the fuel pump relay from the engine room R/B.
    2. Measure the resistance of the fuel pump relay.

      Standard resistance 

      RESISTANCE SPECIFICATION

      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.

    NG: REPLACE FUEL PUMP RELAY 

    OK: Go to next step 

  7. INSPECT FUEL PUMP 
    1. Check the fuel pump operation (See ON-VEHICLE 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 F15 fuel pump connector.
      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) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Fuel pump (F15-4) - Engine room R/B (Fuel pump relay terminal 4) Below 1 Ω

        Standard resistance (Check for short) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Fuel pump (F15-4) 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.
      Fig 4: Identifying F15 Fuel Pump Connector Terminals
      G05264285Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
      1. Disconnect the F15 fuel pump connector.
      2. Measure the resistance between the wire harness side connector and body ground.

        Standard resistance (Check for open) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Engine room R/B (Fuel pump relay terminal 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) 
    Fig 5: Identifying Engine Room R/B Relay Terminals
    G04968187Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    1. Remove the circuit opening relay 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) 

      RESISTANCE SPECIFICATION

      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) 

      RESISTANCE SPECIFICATION

      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.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

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

  10. INSPECT FUEL PUMP RELAY 
    Fig 6: Identifying Fuel Pump Relay Terminals
    G04829434Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    1. Remove the fuel pump relay from the engine room R/B.
    2. Measure the resistance of the fuel pump relay.

      Standard resistance 

      RESISTANCE SPECIFICATION

      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.

    NG: REPLACE FUEL PUMP RELAY 

    OK: Go to next step 

  11. INSPECT FUEL PUMP RESISTOR (RESISTANCE) 
    1. Inspect the fuel pump resistor resistance.
      Fig 7: Identifying Fuel Pump Resistor
      G04968189Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
      1. Measure the resistance of the terminals.

        Resistance: 

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

    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 F6 fuel pump resistor connector.
      3. Check the resistance between the wire harness side connectors.

        Standard resistance (Check for open) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Engine room R/B (Fuel pump relay terminal 5) - Fuel pump resistor (F6-1) Below 1 Ω

        Standard resistance (Check for short) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Engine room R/B (Fuel pump relay terminal 5) or Fuel pump resistor (F6-1) - Body ground 10 kΩ or higher
      4. Reinstall the fuel pump relay.
      5. Reconnect the fuel pump resistor connector.
    2. Check the harness and connector between the fuel pump resistor and fuel pump.
      1. Disconnect the F6 fuel pump resistor connector.
      2. Disconnect the F15 fuel pump connector.
      3. Check the resistance between the wire harness side connectors.

        Standard resistance (Check for open) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Fuel pump resistor (F6-2) - Fuel pump (F15-4) Below 1 Ω

        Standard resistance (Check for short) 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Fuel pump resistor (F6-2) or Fuel pump (F15-4) - Body ground 10 kΩ or higher
    3. Reconnect the fuel pump resistor connector.
      Fig 8: Identifying Fuel Pump Resistor Connector & Fuel Pump Connector Terminal
      G05264289Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    4. Reconnect the fuel pump connector.

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

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals