2007 Lexus RX 400h AWDFACTORY OEM SERVICE PROCEDURE

Fuel System: Precaution

  1. PRECAUTION 
    1. Before inspecting and repairing the fuel system, disconnect the 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 
    NOTE:
    • 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 or a piece of cloth over fittings to prevent fuel from splashing on yourself or in the engine compartment when separating the fittings.
    1. When using the intelligent tester:
      1. Connect the intelligent tester to the DLC3.
      2. Put the vehicle in the "inspection mode". (See REPAIR INSTRUCTION )
      3. Turn the ignition switch ON.
      4. Turn the tester to the ON position.
      5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST.
      6. Perform the ACTIVE TEST by referring to the table below.
        INTELLIGENT TESTER SPECIFICATION

        Intelligent Tester Displays Test Details Control Ranges
        FUEL PUMP/SPD Activate fuel pump (C/OPN Relay) ON/OFF
      7. Turn the fuel pump (C/OPN relay) off.
      8. Turn the ignition switch off immediately after the engine comes to a "rough idle state".
      NOTE: The hybrid system has a complicated process from "out of gas" to "engine stall". Therefore, "rough idle" is regarded as "stop".

      HINT:

      DTCs P0171/25 and P0174/25 indicating LEAN errors may be detected.

    2. When not using the intelligent tester (using C/OPN RLY):
      1. Disconnect the relay block No.3.
      2. Remove the junction block cover No.2.
      3. Remove the C/OPN RLY.
      4. Put the vehicle in the "inspection mode". (See REPAIR INSTRUCTION )
      5. Start the engine.
      6. Turn the ignition switch off immediately after the engine comes to the "rough idle state".
        NOTE: The hybrid system has a complicated process from "out of gas" to "engine stall". Therefore, "rough idle" is regarded as "stop".

        HINT:

        DTCs P0171/25 and P0174/25 indicating LEAN errors may be detected.

      7. Disconnect the negative (-) battery terminal cable.
      8. Install the C/OPN RLY.
      Fig 1: Identifying C/OPN RLY
      G05200828Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. FUEL SYSTEM 
    1. When disconnecting the high fuel pressure line, a large amount of gasoline will spill out. Observe the following procedures:
      1. Discharge the fuel system pressure. (step 2)
      2. Disconnect the fuel tube.
      3. Drain the fuel that remains inside the fuel tube.
      4. Cover the disconnected fuel tubes with a plastic bag to prevent damage and foreign objects from entering the fuel line.
      5. Place a tray under the vehicle or connecting part to catch any fuel that may spill.
      Fig 2: Covering Connector With Plastic Bag
      G05200829Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Observe the following precautions when removing and installing fuel injectors:
      1. Never reuse the O-rings.
      2. When placing a new O-ring on the injector, do not damage the O-ring.
      3. Coat new O-rings with grease or gasoline before installation. Do not use engine oil, gear oil or brake fluid.
      Fig 3: Identifying Correct Way Of Fuel Injectors Installation
      G05200830Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Install the injector with the delivery pipe to the cylinder head as shown in the illustration.
      NOTE: Before installing the injector, be sure to apply grease or gasoline where the delivery pipe or cylinder head contacts an O-ring of the injector.
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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.