LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Scion >> 2012 >> iQ >> Repair and Diagnosis >> Engine Mechanical >> Fuel System >> Fuel System (Inspection) >> Fuel System >> Precaution >> Precaution
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fuel System: Precaution: Precaution

  1. PRECAUTIONS 
    1. Before working on the fuel system, disconnect the cable from the negative battery terminal.
    2. Do not work on the fuel system near any open flames. Never smoke when working on this system.
    3. Keep rubber and leather parts away from gasoline.
  2. DISCHARGE FUEL SYSTEM PRESSURE 
    WARNING:
    • Perform this procedure when the engine coolant temperature is below 60°C (140°F).
    • Perform the following procedure to prevent fuel from spilling out before removing any fuel system parts.
    • Even after discharging the fuel pressure, when disconnecting a fuel line, cover it with a piece of cloth to prevent fuel from spraying or coming out.
    1. Peel back the floor carpet under the front left seat, and disconnect the fuel tank wire connector.
      Fig 1: Locating Fuel Tank Wire Connector
      GTY344681Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Start the engine.
    3. After the engine stops naturally, turn the ignition switch off.
      NOTE:

      Do not increase the engine speed or drive the vehicle while waiting for the engine to stop naturally.

      HINT: 

      DTC P0171 may be set.

    4. Crank the engine again and make sure that the engine does not start.
    5. Remove the fuel tank cap and discharge the pressure from the fuel tank.
    6. Disconnect the cable from the negative battery terminal.
    7. Connect the fuel tank wire connectors.
  3. FUEL SYSTEM 
    1. When disconnecting the high-pressure fuel line, a large amount of gasoline will splash out. Take the following precautions.
      1. Discharge the fuel system pressure.
      2. Remove the fuel tube clip.
      3. Disconnect the fuel tube.
      4. Drain the fuel remaining inside the fuel pump tube into a connector.
      5. Protect the contact surface by covering it with a plastic bag.
        Fig 2: Identifying High Pressure Fuel Line And Plastic Bag
        GTY179516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *1 Plastic Bag
        NOTE:

        Do not damage the pipe or fuel tube connector, and prevent entry of foreign objects.

    2. Observe the following precautions when disconnecting the fuel tube connector (Quick Type A).
      Fig 3: Identifying Fuel Tube Connector (Quick Type A)
      GTY344666Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Remove the No. 1 fuel pipe clamp.
      2. Check for dirt or other foreign matter on the parts to be disconnected and clean them if necessary.
      3. Pinch the retainer of the fuel tube connector, and then pull out the fuel tube connector to disconnect the fuel tube from the fuel pipe.
        Fig 4: Disconnecting Fuel Tube From Fuel Pipe
        GTY345672Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *1 Retainer
        *2 O-Ring
        Pinch
        Pull Out
        NOTE:

        Do not use any tools.

      4. If the connector and pipe are stuck, pinch the retainer with your hand, and then push and pull the connector to disconnect them.
        Fig 5: Identifying Connector, Pipe And Retainer
        GTY181000Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        Push
        Pull
        NOTE:

        Do not use any tools.

      5. Check the sealing surfaces of the disconnected parts, and clean them if necessary.
      6. Protect the contact surface by covering it with a plastic bag.
        Fig 6: Identifying Connector And Plastic Bag
        GTY189677Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *1 Plastic Bag
        NOTE:

        Do not damage the pipe or fuel tube connector, and prevent entry of foreign objects.

    3. Observe the following precautions when connecting the fuel tube connectors (Quick Type A).
      Fig 7: Pushing/Pulling Fuel Tube Connectors (Quick Type A)
      GTY346099Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check that there are no scratches or foreign objects on the connecting part.
      2. Line up the pipe and connector and push them together until a "click" sound is heard.
        TEXT IN ILLUSTRATION

        *a Push
        *b Pull

        HINT: 

        If the pipe is difficult to push into the connector, apply a small amount of clean engine oil to the tip of the pipe and reinsert it.

      3. After connecting the pipes, check that the pipe and connector are securely connected by pulling on them.
        Fig 8: Checking Pipe And Connector Secure Connection
        GTY168714Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Install the No. 1 fuel pipe clamp.
      5. Inspect for fuel leaks.
    4. Observe the following procedure when disconnecting the fuel tube connectors (Quick Type B).
      Fig 9: Disconnecting Fuel Tube Connectors (Quick Type B)
      GTY344872Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check for dirt or other foreign matter on the parts to be disconnected and clean them if necessary.
        TEXT IN ILLUSTRATION

        *1 Retainer
        *2 Claw
        Pinch
        Pull Out
      2. Pinch the tabs of the fuel tube connector retainer to disengage the 2 claws. Push the retainer down to disconnect the fuel tube connector from the pipe.
        NOTE:

        Do not use any tools.

      3. If the connector and pipe are stuck, hold the fuel pipe by hand and push and pull on the connector. Pull the two pipes apart to separate the connector.
        Fig 10: Pulling The Two Pipes Apart
        GTY347025Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        Push
        Pull
        NOTE:

        Do not use any tools.

      4. Check the sealing surfaces of the disconnected parts, and clean them if necessary.
      5. Protect the contact surface by covering it with a plastic bag.
        Fig 11: Covering Disconnected Pipe And Connector With Plastic Bag
        GTY211178Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *1 Plastic Bag
        NOTE:

        Do not damage the pipe or fuel tube connector, and prevent entry of foreign objects.

    5. Observe the following procedure when connecting the fuel tube connector (Quick Type B).
      Fig 12: Connecting The Fuel Tube Connector (Quick Type B)
      GTY347327Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check that there are no scratches or foreign objects on the connecting part.
        TEXT IN ILLUSTRATION

        *1 Retainer
        *2 Claw
        Push
      2. Line up the pipe and connector and push them together until a "click" sound is heard.

        If the pipe is difficult to push into the connector, apply a small amount of clean engine oil to the tip of the pipe and reinsert it.

      3. After connecting the pipes, check that the pipe and connector are securely connected by pulling on them.
      4. Inspect for fuel leaks.
    6. Observe the following procedure when disconnecting the fuel tube connectors (Quick Type C).
      Fig 13: Disconnecting Fuel Tube Connectors (Quick Type C)
      GTY347299Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check for dirt or other foreign matter on the parts to be disconnected and clean them if necessary.
        TEXT IN ILLUSTRATION

        *1 Retainer
        Pull
        Pull Out
      2. Pull the tabs of the fuel tube connector retainer as shown in the illustration to disconnect the fuel tube connector from the pipe.
        NOTE:

        Do not use any tools.

      3. If the connector and pipe are stuck, hold the fuel pipe by hand and push and pull on the connector. Pull the two pipes apart to separate the connector.
        Fig 14: Pulling The Two Pipes Apart
        GTY346108Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        Push
        Pull
        NOTE:

        Do not use any tools.

      4. Check the sealing surfaces of the disconnected parts, and clean them if necessary.
      5. Protect the contact surface by covering it with a plastic bag.
        Fig 15: Covering Contact Surface With Plastic Bag
        GTY346827Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *1 Plastic Bag
        NOTE:

        Do not damage the pipe or fuel tube connector, and prevent entry of foreign objects.

    7. Observe the following procedure when connecting the fuel tube connector (Quick Type C).
      Fig 16: Connecting The Fuel Tube Connector (Quick Type C)
      GTY344716Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check that there are no scratches or foreign objects on the connecting part.
        TEXT IN ILLUSTRATION

        *1 Retainer
        Push
      2. Line up the pipe and connector and push them together until a "click" sound is heard.

        If the pipe is difficult to push into the connector, apply a small amount of clean engine oil to the tip of the pipe and reinsert it.

      3. After connecting the pipes, check that the pipe and connector are securely connected by pulling on them.
      4. Inspect for fuel leaks.
    8. Observe the following procedure when disconnecting the fuel tube connectors (Quick Type D).
      Fig 17: Disconnecting The Fuel Tube Connectors (Quick Type D)
      GTY347135Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check for dirt or other foreign matter on the parts to be disconnected and clean them if necessary.
        TEXT IN ILLUSTRATION

        *1 Retainer
        *2 Claw
        Pull
        Pull Out
      2. Pull the tabs of the fuel tube connector retainer to disengage the 2 claws. Pull the retainer up to disconnect the fuel tube connector from the pipe.
        NOTE:

        Do not use any tools.

      3. If the connector and pipe are stuck, hold the fuel pipe by hand and push and pull on the connector. Pull the two pipes apart to separate the connector.
        Fig 18: Pulling The Two Pipes Apart
        GTY345566Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        Push
        Pull
        NOTE:

        Do not use any tools.

      4. Check the sealing surfaces of the disconnected parts, and clean them if necessary.
      5. Protect the contact surface by covering it with a plastic bag.
        Fig 19: Covering Contact Surface With A Plastic Bag
        GTY346496Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *1 Plastic Bag
        NOTE:

        Do not damage the pipe or fuel tube connector, and prevent entry of foreign objects.

    9. Observe the following procedure when connecting the fuel tube connector (Quick Type D).
      Fig 20: Connecting The Fuel Tube Connector (Quick Type D)
      GTY347145Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Check that there are no scratches or foreign objects on the connecting part.
      2. Line up the pipe and connector and push them together until a "click" sound is heard. If the pipe is difficult to push into the connector, apply a small amount of clean engine oil to the tip of the pipe and reinsert it.
        TEXT IN ILLUSTRATION

        *1 Retainer
        *2 Claw
        Push
        Push
      3. After connecting the pipes, check that the pipe and connector are securely connected by pulling on them.
      4. Inspect for fuel leaks.
  4. INJECTOR 
    1. Observe the following precautions when removing and installing the fuel injector.
      Fig 21: Identifying Correct Fuel Injector Installed Connection
      GTY340677Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Do not reuse the O-ring and insulator.
      2. When placing a new O-ring onto the injector, do not damage the O-ring.
      3. Coat the new O-ring with gasoline or spindle oil before installing it. Do not use engine, gear or brake oil.
    2. Install the injector into the delivery pipe and cylinder head, as shown in the illustration. Apply gasoline or spindle oil to the contact surfaces of the delivery pipe and the injector before installing the injector.
      Fig 22: Identifying O-Ring And Insulator
      GTY346435Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 O-ring
      *2 Insulator
      *3 Delivery pipe
  5. INSPECT FOR FUEL LEAK 
    1. Check that there is no fuel leakage after performing maintenance anywhere on the fuel system See step  1.
scientia non olet · About LEMON Manuals