2012 Toyota Avalon BaseFACTORY OEM SERVICE PROCEDURE

Fuel System: Precaution: Precaution

  1. EXPRESSIONS OF IGNITION SWITCH 
    1. The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this service information.
      Switch Type Ignition Switch (position) Engine Switch (condition)
      Expression Ignition Switch off LOCK Off
      Ignition Switch on (IG) ON On (IG)
      Ignition Switch on (ACC) ACC On (ACC)
      Engine Start START Start
  2. PRECAUTION 
    1. Before inspecting and repairing the fuel system, disconnect the cable from the negative (-) battery terminal.
    2. Do not smoke or work near fire when handling the fuel system.
    3. Keep gasoline away from rubber or leather parts.
  3. DISCHARGE FUEL SYSTEM PRESSURE 
    WARNING:
    • Perform the following procedures to prevent fuel from spilling out before removing any fuel system parts.
    • Pressure will still remain in the fuel line even after performing the following procedures. When disconnecting the fuel line, cover with a shop rag or a piece of cloth to prevent fuel from spraying or spewing out.
    1. Disconnecting the fuel pump connector.
      Fig 1: Identifying Fuel Pump Connector
      GTY124030Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Remove the rear seat cushion assembly.
      2. Remove the rear floor service hole cover.
      3. Disconnect the fuel pump connector.
      4. Start the engine.
      5. After the engine stops, turn the ignition switch off.

        HINT: 

        DTC P0171/25 (fuel problem) may be detected.

      6. Crank the engine again. Check that the engine does not start.
      7. Remove the fuel tank cap to discharge pressure from the fuel tank.
      8. Disconnect the cable from the negative (-) battery terminal.
      9. Reconnect the fuel pump connector.
      10. Install the rear floor service hole cover.
      11. Install the rear seat.
  4. FUEL SYSTEM 
    1. When disconnecting the high fuel pressure line, a large amount of gasoline will spill out, so observe the following procedures:
      1. Discharge the fuel system pressure. (step 3)
      2. Disconnect the fuel pump tube. Refer to REMOVAL - Step 5 .
      3. Drain the fuel that remains inside the fuel pump tube.
      4. To protect the disconnected fuel pump tube from damage and contamination, cover it with a plastic bag.
        Fig 2: Covering Fuel Pump Main Tube With Plastic Bag
        GTY134272Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      5. Put a container under the connection part.
    2. Observe the following precautions when removing and installing fuel injectors:
      Fig 3: Identifying Fuel Injectors O-Ring Correct/Incorrect Fitment
      GTY191292Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Never reuse the O-ring.
      2. When placing a new O-ring on the injector, do not damage the O-ring.
      3. Coat a new O-ring with spindle oil or gasoline before installing.
        NOTE:

        Do not use engine oil, gear oil or brake fluid.

    3. Install the injector to the delivery pipe and lower intake manifold as shown in the illustration.
      Fig 4: Identifying Injector To Delivery Pipe Correct Installation
      GTY146468Courtesy 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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