2004 Toyota Sienna CEFACTORY OEM SERVICE PROCEDURE

Engine Fuel System: Precaution

  1. PRECAUTION 
    1. Before working on fuel system, disconnect negative (-) battery cable.
    2. Do not smoke or work near fire when handling the fuel system.
    3. Keep gasoline away from rubber or leather parts.
  2. DISCHARGE FUEL SYSTEM PRESSURE 
    CAUTION:
    • Do not disconnect any part of the fuel system until you have discharged the fuel system pressure.
    • Even after discharging the fuel pressure, place a shop rag over fittings as you separate them to reduce risk of fuel spray on yourself or in the engine compartment.
    1. Remove the circuit opening relay from the engine room relay block.
      2. Fig 1: Identifying Circuit Opening Relay
      G03061961Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Start the engine. After the engine stopped, turn the ignition switch OFF.

      HINT:

      It is possible that DTC P0171 (system too lean) will be set.

    3. Check that the engine does not start.
    4. Remove the fuel tank cap, and let the air out of the fuel tank.
    5. Disconnect the negative (-) battery cable.
    6. Reinstall the circuit opening relay.
  3. FUEL SYSTEM 
    1. When disconnecting the high fuel pressure line, a large amount of gasoline will spill out, so observe these procedures.
      1. Discharge fuel system pressure. See step  2.
      2. Disconnect the fuel pump tube.

        See REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY .

      3. Drain the fuel that remained inside the fuel pump tube.
      4. Cover the disconnected fuel pump tubes with a vinyl or a plastic bag to prevent damage and dirt.
        5. Fig 2: Cover With Vinyl Or Plastic Bag
        G03061962Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      5. Place a tray under the vehicle or point of disconnection to catch any fuel that may spill.
    2. Observe the following precautions when removing and installing fuel injectors.
      Fig 3: Installing Fuel Injectors
      G03061963Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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