Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2007 Lexus RX 400h FWDFACTORY OEM SERVICE PROCEDURE

Fuel System: Precaution

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.

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.

When using the intelligent tester:

Connect the intelligent tester to the DLC3.
Put the vehicle in the "inspection mode". (See REPAIR INSTRUCTION )
Turn the ignition switch ON.
Turn the tester to the ON position.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST.

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

Turn the fuel pump (C/OPN relay) off.
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.

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
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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
  Courtesy 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
  Courtesy 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.

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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