Where is the fuel pump relay on a Lexus GS300?

The fuel pump relay on a Lexus GS300 is typically located in the engine compartment, often near the fuse box or the battery. The fuel pump relay is an important component that controls the operation of the fuel pump, which is responsible for delivering fuel from the fuel tank to the engine.

Understanding the Fuel Pump Relay

The fuel pump relay is an electronic switch that turns the fuel pump on and off based on signals from the vehicle's computer. When the engine is running, the computer sends a signal to the fuel pump relay, which then closes the circuit and allows the fuel pump to operate. When the engine is turned off, the computer sends a signal to the fuel pump relay to open the circuit, which stops the fuel pump from running.

Locating the Fuel Pump Relay on a Lexus GS300

The exact location of the fuel pump relay on a Lexus GS300 can vary depending on the model year and specific vehicle configuration. However, in general, the fuel pump relay is typically located in the engine compartment, often near the fuse box or the battery. 1 2

To locate the fuel pump relay, you can refer to the owner's manual or the wiring diagram for your specific Lexus GS300 model. The manual or diagram should provide the exact location of the fuel pump relay, as well as other important information about the vehicle's electrical system.

Checking and Replacing the Fuel Pump Relay

• If you suspect that the fuel pump relay is malfunctioning, you can check it by using a multimeter to test the relay's continuity and voltage.


• If the relay is found to be faulty, it will need to be replaced. Replacing the fuel pump relay is a relatively straightforward process, but it's important to follow the manufacturer's instructions and use the correct replacement part.


• It's also a good idea to have the fuel system inspected by a qualified mechanic if you suspect a problem with the fuel pump or the fuel pump relay.

By understanding the location and function of the fuel pump relay on your Lexus GS300, you can more effectively diagnose and address any issues related to the vehicle's fuel system.

Where is the fuel pump relay located?

The fuel pump relay is most commonly located in the fuse/relay box under the hood, though older cars may have it behind the dashboard or under the driver's side kick panel. The exact location varies by vehicle, so your best bet is to consult your owner's manual or search online for your specific make and model.
 
This video shows how to locate the fuel pump relay in a car: 21sPhillips VisionYouTube · Jan 3, 2022
Common locations

• Under the hood: Look for a black plastic box, often near the battery, that contains fuses and relays. A diagram on the lid will identify each component. 
• Under the dashboard: Some vehicles, especially older ones, may have the relay behind the instrument panel or under the driver's side of the dashboard. 
• Driver's side kick panel: In many cases, you can find the relay behind a plastic cover on the driver's side, near where your feet would be. 

This video shows how to find the fuel pump relay in a car: 56sCarsNToysYouTube · Jan 28, 2016
Tips for finding it

• Consult your owner's manual: It will have a diagram showing the precise location of the relay. 
• Search online: Type your vehicle's year, make, and model with "fuel pump relay location" to find specific diagrams and videos. 
• Look for the diagram: Most fuse boxes have a diagram on the inside of the lid that will point out the fuel pump relay. 

Where is the fuel pump control module on a Lexus GS300?

The GS300 has a variable speed controller on the fuel pump that's located in the trunk. These controllers are known to go out over time and the fuel pump simply won't run.

Where is the fuel pump relay on a GS300?

The Lexus GS300 fuel pump relay is typically located in the under-hood fuse box. For certain model years, the relay might be on a separate relay board under the dashboard, as described in one source for a different make and model. It's best to first check the under-hood fuse box and refer to the owner's manual or the diagram inside the fuse box cover for the exact location and a diagram.
 
This video shows how to find and remove the fuel pump relay from the under-hood fuse box: 53sAdvance Auto PartsYouTube · Jan 28, 2012

• Primary location: In the main fuse box located in the engine bay, usually near the battery. 
• How to find it: Look for a diagram, often on the inside of the fuse box lid or in the owner's manual, that labels the fuel pump relay. The label may be "F/POP" or similar. 
• Troubleshooting: If you can't find it in the under-hood box, check for another relay board under the dashboard on the driver's side. 
• Testing: You can test the relay by swapping it with a similar relay in the box or by testing it with a multimeter. 
• Related issues: A faulty relay can cause the engine to crank but not start. 

How do I know if my fuel pump relay is blown?

A bad fuel pump relay can be identified by an engine that cranks but won't start, difficulty starting, engine stalling, or a lack of the usual whirring sound from the fuel pump when the ignition is turned on. Other signs include a check engine light, power loss, engine misfires, hesitation during acceleration, and poor fuel efficiency. You can confirm the issue by using a multimeter to test the relay or by swapping it with a known good relay from your vehicle.
 
This video explains the signs of a bad fuel pump relay: 56sMechanical BoostYouTube · Dec 25, 2024
Key symptoms of a bad fuel pump relay

• Engine cranks but won't start: This is one of the most common signs. The relay fails to send power to the fuel pump, so the engine gets no fuel, even though the starter is turning it over. 
• Difficulty starting or no-start condition: If the relay is failing intermittently, the engine may take several tries to start. A complete failure will prevent the engine from starting at all. 
• Sudden engine stalling: The relay may be cutting off power to the fuel pump unexpectedly while driving, causing the engine to stall. 
• No fuel pump sound: When you turn the key to the "on" position (before cranking), you should hear a faint whirring or buzzing sound from the fuel pump as it builds pressure. If you hear nothing, the relay may be the problem. 
• Check engine light is on: A faulty relay can cause a lean air-fuel mixture, which triggers the check engine light. 
• Engine misfires or rough idle: The inconsistent fuel supply from a bad relay can lead to poor combustion, causing misfires and a rough-running engine. 
• Hesitation or power loss: The engine may hesitate or feel sluggish, especially when under load (like accelerating or going uphill), because the fuel pump is not supplying enough fuel. 

You can watch this video to see how to diagnose a failed fuel pump: 0:481A Auto PartsFacebook · Apr 9, 2024
How to test a fuel pump relay

• Swap with a similar relay: Find another relay in your car's fuse box with the same part number (for a non-critical component like the horn or a similar relay) and swap them. If the fuel pump works with the new relay, the original relay is bad. 
• Use a multimeter: 
  • Set your multimeter to the ohms setting. 
  • Touch the leads to the two power terminals on the relay (often terminals 85 and 86). A good relay will show a resistance value between 50 and 120 ohms. An open circuit or a reading outside this range indicates a bad relay. 
  • Set the multimeter to continuity and listen for a beep. Touch the leads to the two power circuit pins (often 30 and 87) and listen for a beep. If you hear one, the power pins have shorted, and the relay needs to be replaced.