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Home >> Lexus >> 2008 >> RX 350 FWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> Fuel Pump Control Circuit >> Inspection Procedure
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Inspection Procedure

  1. CHECK FUEL PUMP 
    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  13

    NG: Go to Next Step 

  2. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE C/OPN RELAY) 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch to the ON position and turn the intelligent tester or the OBD II scan tool main switch on.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP / SPD.
    4. Check the relay operation while operating it using the intelligent tester.

      Standard: Operating noise can be heard from the relay. 

    OK:  Go to step  7

    NG: Go to Next Step 

  3. INSPECT CIRCUIT OPENING RELAY 
    1. Remove the C/OPN relay from the R/B.
    2. Measure the resistance of the C/OPN relay.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      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. Fig 1: Identifying C/OPN Relay Connector Terminals
      G04942983Courtesy 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 to the ON position.
    2. Measure the voltage of the ECM connectors.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      E5-10 (FC) - E7-1 (E1) 9 to 14 V
      3. Fig 2: Identifying E7 And E5 Connectors Terminals
      G05268243Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ECM 

    NG: Go to Next Step 

  5. CHECK HARNESS AND CONNECTOR (ECM - CIRCUIT OPENING RELAY) 
    1. Disconnect the E5 ECM connector.
    2. Remove the C/OPN relay from the engine room R/B.
    3. Measure the resistance between the terminals.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      FC (E5-10) - C/OPN terminal (2) Below 1 Ω

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      FC (E5-10) or C/OPN terminal (2) - Body ground 10 kΩ or higher
    4. Reconnect the ECM connector.
    5. Reinstall the C/OPN relay.
      6. Fig 3: Identifying E5 And C/OPN Relay Connectors Terminals
      G05268244Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  6. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - IGNITION SWITCH) 
    1. Reconnect the 114 ignition switch connector.
    2. Remove the C/OPN relay from the engine room R/B.
    3. Measure the resistance between the terminals.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      IG2 (I14-6) - C/OPN terminal (1) Below 1 Ω

      Standard resistance: 

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      IG2 (I14-6) or C/OPN terminal (1) - Body ground 10 kΩ or higher
    4. Reconnect the ignition switch connector.
    5. Reinstall the C/OPN relay.
      6. Fig 4: Identifying C/OPN Relay And I14 Connectors Terminals
      G05840338Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  7. CHECK ECM POWER SOURCE CIRCUIT 

    NG: REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT 

    OK: Go to Next Step 

  8. INSPECT FUEL PUMP RELAY 
    1. Remove the fuel pump relay from the engine room R/B.
    2. Measure the fuel pump relay resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      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)
      Fig 5: Identifying Fuel Pump Relay Connector Terminals
      G05136045Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reinstall the fuel pump relay.

    NG: REPLACE FUEL PUMP RELAY 

    OK: Go to Next Step 

  9. INSPECT FUEL PUMP 
    1. Measure the resistance of the fuel pump.
      1. Measure the resistance between terminals 4 and 5.

        Standard resistance 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        4 - 5 20°C (68°F) 0.2 to 0.3 Ω
    2. Check operation of the fuel pump.
      1. Apply battery voltage to both terminals. Check that the pump operates.
        Fig 6: Identifying F16 Connector Terminals
        G05268247Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        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 turn ON and OFF the voltage on the battery side, not ON the fuel pump side.

    NG: REPLACE FUEL PUMP ASSEMBLY  (See DISASSEMBLY )

    OK: Go to Next Step 

  10. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP RELAY, FUEL PUMP - BODY GROUND) 
    1. Check the wire harness between the FUEL PUMP relay and fuel pump.
      1. Remove the FUEL PUMP relay from the engine room R/B.
      2. Disconnect the F16 fuel pump connector.
      3. Measure the resistance between the terminal of the wire harness side connectors and body ground.

        Standard resistance 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Specified Condition
        FUEL PUMP relay terminal 4 - F16-4 Below 1 Ω
        FUEL PUMP relay terminal 4 or F16-4 - Body ground 10 kΩ or higher
    2. Check the wire harness between the fuel pump and body ground.
      1. Disconnect the F16 fuel pump connector.
      2. Measure the resistance between the terminal of the wire harness side connector and body ground.

        Standard resistance 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Specified Condition
        F16-5 (Fuel pump) - Body ground Below 1 Ω
        3. Fig 7: Identifying F16 And Fuel Pump Relay Connectors Terminals
        G05268248Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  11. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - FUEL PUMP RELAY) 
    1. Remove the C/OPN 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 terminals.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      C/OPN relay terminal (3) - FUEL PUMP relay terminal (3) Below 1 Ω

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      C/OPN relay terminal (3) or FUEL PUMP relay terminal (3) - Body ground 10 kΩ or higher
      4. Fig 8: Identifying Fuel Pump Relay And C/OPN Relay Connectors Terminals
      G05268249Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: CHECK HARNESS AND CONNECTOR (EFI RELAY - C/OPN RELAY) 

  12. INSPECT FUEL PUMP RELAY 
    1. Remove the FUEL PUMP relay from the engine room R/B.
    2. Measure the FUEL PUMP relay resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      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)
      Fig 9: Identifying Fuel Pump Relay Connectors Terminals
      G05136045Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reinstall the FUEL PUMP relay.

    NG: REPLACE FUEL PUMP RELAY 

    OK: Go to Next Step 

  13. INSPECT FUEL PUMP RESISTOR 
    1. Disconnect the F17 fuel pump resistor connector.
    2. Measure the fuel pump resistor resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 0.30 to 0.34 Ω
    3. Reconnect the fuel pump resistor connector.
      4. Fig 10: Measuring Fuel Pump Resistor Resistance
      G04962581Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE FUEL PUMP RESISTOR 

    OK: Go to Next Step 

  14. CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY - FUEL PUMP RESISTOR) 
    1. Disconnect the F17 fuel pump resistor connector.
    2. Remove the FUEL PUMP relay from the engine room R/B.
    3. Measure the resistance between the terminals.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      FUEL PUMP relay terminal (4) - F17-2 Below 1 Ω
      FUEL PUMP relay terminal (5) - F17-1 Below 1 Ω

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      FUEL PUMP relay terminal (4) or F17-2 - Body ground 10 kΩ or higher
      FUEL PUMP relay terminal (5) or F17-1 - Body ground 10 kΩ or higher
    4. Reconnect the fuel pump resistor connector.
    5. Reinstall the FUEL PUMP relay.
      6. Fig 11: Identifying F17 And Fuel Pump Relay Connectors Terminals
      G05268252Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  15. CHECK HARNESS AND CONNECTOR (FUEL PUMP RESISTOR - FUEL PUMP) 
    1. Disconnect the F17 fuel pump resistor connector.
    2. Disconnect the F16 fuel pump connector.
    3. Measure the resistance between the terminals.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      F17-2 - F16-4 Below 1 Ω

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      F17-2 or F16-4 - Body ground 10 kΩ or higher
    4. Reconnect the fuel pump resistor connector.
    5. Reconnect the fuel pump connector.
      6. Fig 12: Identifying F17 And F16 Connectors Terminals
      G05268253Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

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

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