2002 Lexus ES300 Fuel Pump Relay Location: The Complete Guide to Finding and Fixing It

The bottom line: The fuel pump relay on a 2002 Lexus ES300 is located inside the engine compartment fuse box, which is positioned on the driver's side near the battery. The relay is marked as "EFI" or "Fuel Pump" on the fuse box cover diagram. If your car cranks but won't start, or if you hear no buzzing sound from the fuel tank when you turn the key to the "ON" position, the fuel pump relay is one of the first things you should check.

Understanding the Fuel Pump Relay and Its Role

The fuel pump relay is an electrical switch that controls power to the fuel pump. When you turn the ignition key to the "ON" position, the relay closes and sends battery voltage to the fuel pump for a few seconds to prime the fuel system. Once the engine starts, the relay stays closed to keep the pump running.

If the relay fails, the fuel pump will not receive power, and your engine will not start. This is why knowing the exact location of the 2002 Lexus ES300 fuel pump relay is so important for DIY troubleshooting.

Exact Location of the 2002 Lexus ES300 Fuel Pump Relay

The 2002 Lexus ES300 has two main fuse boxes, but the fuel pump relay is specifically found in the engine compartment fuse box (also called the main fuse box or junction block).

Step-by-Step Instructions to Locate the Relay

  1. Open the hood and secure it with the prop rod.
  2. Look on the driver's side of the engine bay, near the battery. You will see a rectangular black plastic box. This is the engine compartment fuse and relay box.
  3. Remove the cover by pressing the release tabs on the sides and lifting it straight up.
  4. Check the inside of the cover for a diagram. The relay you are looking for is typically labeled "EFI" (Electronic Fuel Injection) or "Fuel Pump." On some models, it may also be labeled as "C/OPN" (Circuit Opening Relay).
  5. The relay itself is a small, square, black or gray component that plugs into the fuse box. It is usually larger than the fuses around it.

Note: The fuel pump relay is not inside the passenger compartment fuse box (located under the dashboard on the driver's side). That box only contains fuses for interior components like the radio, lights, and power windows.

How to Test the Fuel Pump Relay

Before you replace the relay, it is smart to test it first. This saves you time and money.

The Swap Test

  1. Locate the relay labeled "EFI" or "Fuel Pump" in the engine compartment fuse box.
  2. Find another relay in the same fuse box that is the exact same size and shape. Common relays that share the same configuration include the Horn relay, Headlight relay, or A/C relay.
  3. Pull out the fuel pump relay and swap it with one of the other identical relays.
  4. Try to start the car. If it starts now, the original fuel pump relay was bad and needs to be replaced. If the car still does not start, the problem is elsewhere.

The Multimeter Test

If you have a digital multimeter, you can test the relay directly:

  1. Set your multimeter to measure resistance (ohms).
  2. Touch the probes to terminals 85 and 86 on the relay. You should see a reading between 50 and 120 ohms. If you see "OL" (open line) or zero, the coil inside the relay is bad.
  3. Apply 12 volts to terminals 85 and 86 (using a battery or a power supply). You should hear a distinct "click" as the relay engages.
  4. While power is applied, check resistance between terminals 30 and 87. It should read near zero ohms (closed circuit). If it reads "OL" even with power applied, the relay contacts are bad.

Common Symptoms of a Bad Fuel Pump Relay

Knowing the symptoms helps you diagnose the issue faster. If your 2002 Lexus ES300 is experiencing any of these problems, the fuel pump relay could be the culprit:

  • Engine cranks but will not start: This is the most common symptom. The starter motor turns the engine over, but the fuel pump never gets power to pressurize the fuel system.
  • No sound from the fuel tank: When you turn the key to the "ON" position (without cranking the engine), you should hear a faint buzzing or whirring sound from the rear of the car for about 2-3 seconds. This is the fuel pump priming. If you hear nothing, the relay is a likely suspect.
  • Engine stalls while driving: If the relay fails intermittently, the engine may stall unexpectedly while you are driving and then restart after a few minutes. This is a dangerous condition and should be addressed immediately.
  • Check Engine Light comes on: The ECU may store a diagnostic trouble code (DTC) related to the fuel pump circuit, such as P0230 (Fuel Pump Primary Circuit Malfunction).

Other Possible Causes of No Power to the Fuel Pump

If the relay tests good but your fuel pump still has no power, there are other components to check:

  • Blown fuse: Check the "EFI" or "FUEL PUMP" fuse in the engine compartment fuse box. A blown fuse will cut power to the pump entirely.
  • Fuel pump itself: The pump motor inside the tank can fail mechanically or electrically. This is less common than a relay failure, but it does happen, especially on older vehicles.
  • Wiring or connector issues: Corroded or damaged wiring between the relay, fuse, and fuel pump can interrupt power. Check the wiring harness under the car and near the fuel tank for rust, breaks, or loose connections.
  • ECU (Engine Control Unit) failure: In rare cases, the ECU itself fails to send the signal to close the relay. This is a more complex diagnosis and usually requires a professional scan tool.

How to Replace the 2002 Lexus ES300 Fuel Pump Relay

Replacing the relay is a simple, five-minute job that requires no special tools.

  1. Purchase a replacement relay. You can buy one from a Lexus dealer, an auto parts store, or online. The part number for the EFI relay is typically 90987-02006 or a generic equivalent. Always buy a high-quality relay to avoid premature failure.
  2. Locate the relay as described above.
  3. Pull the old relay straight out of its socket. It may require a firm tug, but do not twist or pry it.
  4. Insert the new relay into the same socket. Push it down firmly until it clicks into place.
  5. Replace the fuse box cover and close the hood.
  6. Test the repair by turning the key to "ON" and listening for the fuel pump prime sound. Then start the engine.

Why You Should Buy a KEMSO Fuel Pump for Your 2002 Lexus ES300

If you have determined that your fuel pump itself is the problem, or if you want to replace the entire fuel pump assembly as a preventative measure, you need a reliable, high-performance replacement. That is where KEMSO comes in.

KEMSO is a leading aftermarket brand that specializes in manufacturing premium fuel pumps for a wide range of vehicles, including the 2002 Lexus ES300. Every KEMSO fuel pump is built to OEM specifications (Original Equipment Manufacturer), which means it fits perfectly and performs exactly like the factory part, if not better.

Here is why KEMSO is the right choice for your Lexus:

  • High Performance: KEMSO fuel pumps are designed to deliver consistent fuel pressure and flow, ensuring your engine runs smoothly under all driving conditions.
  • OEM Replacement: You get a direct, plug-and-play fit. No modifications, no adapters, no guesswork.
  • Lifetime Warranty: KEMSO stands behind their products. Every fuel pump comes with a lifetime warranty, giving you total peace of mind. If it ever fails, you get a replacement at no cost.
  • Built to Last: KEMSO uses high-quality materials and rigorous testing to ensure their pumps outlast cheap generic alternatives.

Do not trust your car's fuel system to a low-quality part. Visit KEMSO today to find the perfect fuel pump for your 2002 Lexus ES300 and keep your car running like new.

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