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Home › Toyota › 2008 › Tundra Base, 5.7 V, RWD › Repair and Diagnosis › Engine Performance › Engine Control Systems › Engine Control System (3UR-FE) - System Testing, On-Vehicle Inspection, Removal, Inspection & Installation › Fuel Pump Control Circuit › Inspection Procedure

Inspection Procedure

This troubleshooting procedure is based on the premise that the engine is started. If the engine is not started, proceed to the problem symptoms table (see PROBLEM SYMPTOMS TABLE ).

  1. PERFORM ACTIVE TEST USING TECHSTREAM (FUEL PUMP) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON and turn the Techstream ON.
    3. Enter the following menus: Powertrain/Engine and ECT/Active Test/Control the Fuel Pump/Speed.
    4. Check whether operating sounds can be heard while operating the relay using the Techstream.

      OK: Operating sounds can be heard from relay. 

    NG :  Go to step  5

    OK : Go to next step 

  2. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM AND BODY GROUND) 
    1. Disconnect the R7 fuel pump ECU connector.
    2. Disconnect the A24 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      R7-1 (FPC) - A24-52 (FPC) Always Below 1 Ω
      R7-2 (DI) - A24-18 (DI) Always Below 1 Ω
      R7-3 (E) - Body ground Always Below 1 Ω
      R7-1 (FPC) or A24-52 (FPC) - Body ground Always 10 kΩ or more
      R7-2 (DI) or A24-18 (DI) - Body ground Always 10 kΩ or more

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Identifying R7 Fuel Pump ECU & A24 ECM Connector Terminals
    G05681651Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  3. REPLACE FUEL PUMP ECU 
    1. Replace the fuel pump ECU. (See FUEL PUMP ECU ).
  4. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 
    1. Check the fuel pump operation.

      OK: Malfunction has been repaired successfully. 

    NG : REPLACE ECM  (See REMOVAL  )

    OK : END 

  5. INSPECT CIRCUIT OPENING RELAY (C/OPN) 
    1. Remove the circuit opening relay (C/OPN) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    2. Measure the resistance according to the value(s) in the table below.
      Fig 2: Inspecting Circuit Opening Relay (C/OPN)
      G05681652Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      3-5 When no battery voltage applied to terminals 1 and 2 10 kΩ or higher
      3-5 When battery voltage applied to terminals 1 and 2 Below 1 Ω

    NG : REPLACE CIRCUIT OPENING RELAY (C/OPN)  (See ON-VEHICLE INSPECTION  )

    OK : Go to next step 

  6. INSPECT CIRCUIT OPENING RELAY (POWER SOURCE VOLTAGE) 
    1. Remove the circuit opening relay (C/OPN) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      C/OPN relay (2) - Body ground Ignition switch ON 11 to 14 V
      C/OPN relay (5) - Body ground Ignition switch ON 11 to 14 V

    NG :  Go to step  13

    Fig 3: Inspecting Circuit Opening Relay (Power Source Voltage)
    G05681653Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  7. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - ECM AND FUEL PUMP ECU) 
    1. Remove the circuit opening relay (C/OPN) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    2. Disconnect the A24 ECM connector.
    3. Disconnect the R7 fuel pump ECU connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      C/OPN relay (1) - A24-48 (FC) Always Below 1 Ω
      C/OPN relay (3) - R7-4 (+B) Always Below 1 Ω
      C/OPN relay (1) or A24-48 (FC) - Body ground Always 10 kΩ or higher
      C/OPN relay (3) or R7-4 (+B) - Body ground Always 10 kΩ or higher

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 4: Identifying R7 Fuel Pump ECU & A24 ECM Connector Terminals
    G05681654Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  8. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP ECU) 
    1. Disconnect the R6 fuel pump connector.
    2. Disconnect the R8 fuel pump ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      R6-4 (B2) - R8-1 (FP) Always Below 1 Ω
      R6-5 (E2) - R8-2 (FP-) Always Below 1 Ω
      R6-4 (B2) or R8-1 (FP) - Body ground Always 10 kΩ or higher
      R6-5 (E2) or R8-2 (FP-) - Body ground Always 10 kΩ or higher

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 5: Identifying R6 Fuel Pump & R8 Fuel Pump ECU Connector Terminals
    G05681655Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  9. INSPECT FUEL PUMP 
    1. Inspect the fuel pump. (See INSPECTION ).

    NG : REPLACE FUEL PUMP  . (See FUEL PUMP ).

    OK : Go to next step 

  10. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM AND BODY GROUND) 
    1. Disconnect the R7 fuel pump ECU connector.
    2. Disconnect the A24 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      R7-1 (FPC) - A24-52 (FPC) Always Below 1 Ω
      R7-2 (DI) - A24-18 (DI) Always Below 1 Ω
      R7-3 (E) - Body ground Always Below 1 Ω
      R7-1 (FPC) or A24-52 (FPC) - Body ground Always 10 kΩ or more
      R7-2 (DI) or A24-18 (DI) - Body ground Always 10 kΩ or more

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 6: Identifying R7 Fuel Pump ECU & A24 ECM Connector Terminals
    G05681656Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  11. REPLACE FUEL PUMP ECU 
    1. Replace the fuel pump ECU. (See FUEL PUMP ECU ).
  12. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 
    1. Check the fuel pump operation.

      OK: Malfunction has been repaired successfully. 

    NG : REPLACE ECM  (See REMOVAL  )

    OK : END 

  13. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - FUEL PUMP RELAY AND IGN FUSE) 
    1. Remove the circuit opening relay (C/OPN) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    2. Remove the fuel pump relay (F/PMP) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    3. Remove the IGN fuse from the engine room relay block.
    4. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      C/OPN relay (2) - IGN fuse (2) Always Below 1 Ω
      C/OPN relay (5) - F/PMP relay (3) Always Below 1 Ω
      C/OPN relay (2) or IGN fuse (2) - Body ground Always 10 kΩ or more
      C/OPN relay (5) or F/PMP relay (3) - Body ground Always 10 kΩ or more

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 7: Checking Fuel Pump Relay (F/PMP) From Engine Room Relay Block
    G05681657Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  14. INSPECT FUEL PUMP RELAY (F/PMP) 
    1. Remove the fuel pump relay (F/PMP) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      3-5 When no battery voltage applied to terminals 1 and 2 10 kΩ or higher
      3-5 When battery voltage applied to terminals 1 and 2 Below 1 Ω
      Fig 8: Inspecting Fuel Pump Relay (F/PMP)
      G05681658Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG : REPLACE FUEL PUMP RELAY (F/PMP)  (See ON-VEHICLE INSPECTION  )

    OK : Go to next step 

  15. CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY - INTEGRATION RELAY, BATTERY AND BODY GROUND) 
    1. Remove the IGN fuse from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      F/PMP fuse Always Below 1 Ω
    3. Reinstall the F/PMP fuse.
    4. Remove the fuel pump relay (F/PMP) from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    5. Remove the integration relay from the engine room relay block (see ON-VEHICLE INSPECTION  ).
    6. Disconnect the 1B integration relay connector.
    7. Disconnect the cable from the battery positive (+) terminal.
    8. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      F/PMP relay (1) - 1B-4 Always Below 1 Ω
      F/PMP relay (5) - Positive (+) battery cable Always Below 1 Ω
      F/PMP relay (2) - Body ground Always Below 1 Ω
      F/PMP relay (1) or 1B-4 - Body ground Always 10 kΩ or higher
      F/PMP relay (5) or Positive (+) battery cable - Body ground Always 10 kΩ or higher
      Fig 9: Checking Harness & Connector (Fuel Pump Relay - Integration Relay, Battery & Body Ground)
      G05681659Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK : GO TO ECM POWER SOURCE CIRCUIT 

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