2002 Toyota Highlander Fuel Pump Relay Location: A Complete Guide for DIY Owners

The fuel pump relay on a 2002 Toyota Highlander is located in the engine compartment fuse box, which sits on the left side of the engine bay near the battery. This small but critical component controls the electrical current that powers the fuel pump, and knowing exactly where to find it can save you hours of frustration when your Highlander has trouble starting, stalls unexpectedly, or loses power while driving.

The 2002 Toyota Highlander, part of the first generation (also known as the XU20 platform), has three different fuse boxes: one in the engine compartment, one in the instrument panel, and one for the daytime running light system. The fuel pump relay is not a separate standalone unit—it is actually integrated into the engine compartment relay box and is often referred to as the "Circuit Opening Relay" or the "EFI Main Relay" in Toyota service manuals. Understanding this distinction is key to locating and testing the part correctly.

Where Exactly Is the Fuel Pump Relay Located?

The fuel pump relay on a 2002 Toyota Highlander is located inside the engine room relay block (engine compartment fuse box) on the left side of the engine compartment. This box is mounted near the battery and the left front strut tower. Open the hood, look toward the driver's side (left side when facing the vehicle), and you will see a black plastic box with a removable cover. The cover has a diagram printed on the inside that shows the position of each relay and fuse.

Inside this box, the fuel pump relay is typically labeled as the "Circuit Opening Relay" or sometimes just the "EFI Relay." In the factory wiring diagrams, this relay is responsible for providing power to the fuel pump when the engine is cranking or running. The EFI main relay and the circuit opening relay work together to control the fuel delivery system. According to the official Toyota service manual for the 2002 Highlander, the circuit opening relay is located in the engine room junction block, and it controls the ground circuit for the fuel pump relay. When the Engine Control Module (ECM) receives proper input signals from the starter and crankshaft position sensor, it grounds the FC terminal, which energizes the circuit opening relay and allows voltage to reach the fuel pump.

Understanding the 2002 Highlander Fuse Box Layout

Before you start digging around the fuse box, it helps to understand the full layout. The 2002 Toyota Highlander fuse box diagram shows the engine compartment contains over 50 fuses and relays. The relay you are looking for is not a standard mini fuse—it is a larger relay with four or five terminals that plugs into the relay block.

The engine compartment fuse box includes several important relays, including:

  • U9: M/G CLT Relay (magneto clutch)
  • U10: Horn Relay
  • U11: EFI Relay (this is closely related to the fuel pump circuit)
  • U12: ABS Motor Relay
  • U13: ABS Solenoid Relay
  • U14: A/F Heater Relay
  • U15: Fan Relay No. 2
  • U16: Fan Relay No. 3
  • U17: Fan Relay No. 1
  • U18: Starter Relay
  • U20: RR Def Relay (rear defogger)
  • U22: Head Relay

The EFI relay (U11) is the one most directly tied to the fuel pump circuit. When the ignition is turned on, the EFI main relay energizes and provides battery voltage to both sides of the circuit opening relay. The circuit opening relay then waits for the ECM to ground its circuit before delivering power to the fuel pump.

What Does the Fuel Pump Relay Actually Do?

The fuel pump relay is an electromechanical switch that acts as a gatekeeper for the electrical current going to the fuel pump. Here is how it works in simple terms:

  1. When you turn the key to the "ON" position, the ECM checks for signals from the ignition system. The fuel pump relay is not immediately energized at this point.
  2. When you crank the engine, the starter signal (STA) and the crankshaft rotation signal (NE) are sent to the ECM.
  3. The ECM then grounds the circuit opening relay through the FC terminal, which completes the circuit and allows full battery voltage to reach the fuel pump.
  4. The fuel pump spins up and pressurizes the fuel rail so the engine can start.
  5. If the engine stalls or the airbag deploys in a collision, the fuel pump shut off system stops supplying fuel to minimize fire risk. To restart the engine after this system activates, you simply need to turn the ignition switch to "ACC" or "LOCK" once and then start the engine.

This system is designed for safety. If the engine stops running unexpectedly, the fuel pump relay de-energizes and stops the flow of fuel, reducing the risk of a fire in a crash.

How to Identify a Failing Fuel Pump Relay

If your 2002 Toyota Highlander is having fuel delivery problems, the relay is a good place to start troubleshooting before you replace the fuel pump itself. Replacing a relay is much cheaper and easier than dropping the fuel tank to replace the pump. Here are the common symptoms of a bad fuel pump relay:

1. Engine Cranks but Does Not Start
This is the most common symptom. You turn the key, the starter motor spins the engine, but the engine never fires up. You may not hear the fuel pump prime when you turn the key to the "ON" position. In a properly working system, you should hear a brief whirring sound from the rear of the vehicle for about two seconds when the key is first turned to "ON." If you do not hear this sound, the relay may not be sending power to the pump.

2. Engine Starts Then Dies Immediately
Sometimes the relay works intermittently. The engine may start and run for a second or two, then stall. This happens because the relay momentarily provides power to the pump, but then loses contact or fails to maintain the circuit.

3. Sudden Stalling While Driving
If the relay fails while you are driving, the engine will lose power and stall with no warning. This is dangerous, especially in traffic. The good news is that if the relay is the problem, the engine will usually restart after a few minutes when the relay cools down and makes contact again.

4. No Fuel Pump Prime Sound
When you turn the key to "ON" (without cranking), the fuel pump should run for about two seconds to pressurize the system. If you do not hear the pump running from the rear of the vehicle, the relay is one of the first things to check.

5. Check Engine Light Comes On
A failing relay can trigger diagnostic trouble codes related to the fuel system. Common codes include P0230 (Fuel Pump Primary Circuit Malfunction) or codes related to fuel pressure.

How to Test the Fuel Pump Relay

Testing the fuel pump relay is straightforward and requires only a few basic tools: a multimeter, a set of jumper wires, and a 12-volt power source like the car battery. Follow these steps carefully:

Step 1: Locate and Remove the Relay
Open the hood and find the engine compartment fuse box on the left side. Remove the cover. Locate the EFI relay or circuit opening relay. The relay is usually a square or rectangular block with four or five metal prongs on the bottom. Gently pull it straight up to remove it from the socket. Use a gentle rocking motion if it is stuck.

Step 2: Identify the Relay Terminals
Most fuel pump relays have a diagram printed on the side showing the terminal numbers. Typically, terminals 1 and 2 are the control circuit (coil), and terminals 3, 4, and 5 are the power circuit (switch contacts). If you cannot find a diagram, look at the base of the relay socket. The two smaller wires usually connect to the control circuit terminals, and the larger wires connect to the power circuit terminals.

Step 3: Test the Coil Resistance
Set your multimeter to measure resistance (ohms). Touch the probes to terminals 1 and 2 (the control circuit terminals). You should see a reading between 50 and 120 ohms. If the reading is infinite (open circuit), the relay coil is burned out and the relay needs to be replaced.

Step 4: Test the Switch Contacts
With the relay removed and no power applied, check the resistance between terminals 3 and 4. You should read infinite resistance (open circuit) because the relay is in its normally open state. Then, connect a 12-volt power source to terminals 1 and 2 using jumper wires. Apply power to terminal 1 and ground terminal 2. When the relay clicks, check the resistance between terminals 3 and 4 again. This time, you should read near zero ohms (continuity). If the relay does not click or the contacts do not close, the relay is defective.

Step 5: Check for Voltage at the Relay Socket
If the relay tests good, the problem may be in the wiring. Reinstall the relay and turn the ignition to "ON." Use a voltmeter to check for battery voltage at the appropriate terminals in the relay socket. If you do not see voltage, there may be a blown fuse, a broken wire, or a faulty ECM.

Common Fuses Related to the Fuel Pump Circuit

Before you replace the relay, it is worth checking the related fuses. The 2002 Highlander has several fuses that can affect the fuel pump circuit:

  • EFI Fuse (20A) : This mini fuse is located in the engine compartment fuse box. It is labeled as number 12 and is rated at 20 amps. It protects the multiport fuel injection system, the fuel pump, and the engine immobilizer system.
  • AM2 Fuse (30A) : This is a larger FMX/JCase fuse located in the engine compartment fuse box (number 47). It protects the starting system and the multiport fuel injection system. If this fuse blows, the engine will not start.
  • IG1 Fuse (7.5A) : This fuse is located in the instrument panel fuse box. It powers the ignition system and the gauges.
  • ECU-B Fuse (7.5A) : Located in the engine compartment fuse box (number 11), this fuse powers the ECM's backup memory and the theft deterrent system.

Check each of these fuses visually or with a test light. A blown fuse will have a broken metal strip visible through the clear plastic housing. If you find a blown fuse, replace it with the same amperage rating. Never use a higher amperage fuse, as it can cause wiring damage or fire.

Additional Tools and Diagnostic Tips

If you want to be absolutely sure the relay is the problem, you can use a Toyota hand-held tester or a generic OBD-II scanner with active test capability. According to the factory service manual, you can connect the tester to the data link connector (DLC3) located under the driver's side of the instrument panel. Select the "Active Test Mode" on the tester and operate the fuel pump manually. If the pump operates when commanded by the tester, the relay and wiring are likely fine, and the problem may be in the ECM or the crankshaft position sensor.

If the fuel pump does not operate during the active test, the EFI main relay or circuit opening relay may be defective. You can also bypass the relay temporarily to test the pump directly. If the pump runs when you bypass the relay, the relay is almost certainly bad. If the pump still does not run, the pump itself may be faulty, or there may be a wiring issue between the relay and the pump.

Where to Buy a Replacement Fuel Pump Relay

When it comes to replacing the fuel pump relay on your 2002 Toyota Highlander, you have several options. You can buy an OEM Toyota relay from a dealership or an online parts retailer. The OEM part number for the circuit opening relay is 90080-87010 or 90987-02027. This genuine Toyota part is guaranteed by the manufacturer's warranty and is designed to fit 2001-2025 Toyota Highlander models with various engine configurations including the 2.4L 4-cylinder and the 3.0L V6.

Aftermarket relays are also available and are usually less expensive. Just make sure the relay is rated for the same amperage and has the same pin configuration as the original. The relay should be a standard 30-amp or 40-amp relay with a 4-pin or 5-pin configuration.

Step-by-Step Replacement Guide

Replacing the fuel pump relay is one of the easiest repairs you can do on a 2002 Toyota Highlander. Here is the complete process:

1. Gather Your Tools
You will need the new relay, a pair of pliers (optional), and a flashlight. No special tools are required.

2. Disconnect the Battery
As a safety precaution, disconnect the negative battery terminal before working on any electrical components. This prevents accidental shorts or sparks.

3. Open the Fuse Box
Lift the latch on the engine compartment fuse box cover and remove it. Set the cover aside where you will not lose it.

4. Locate the Relay
Refer to the diagram on the inside of the fuse box cover. The EFI relay or circuit opening relay is clearly marked. If you are unsure, you can also look at the relay's position relative to the other components. The EFI relay is usually a larger relay located near the center of the fuse box.

5. Remove the Old Relay
Grasp the relay firmly and pull it straight up. If it is stuck, use a pair of pliers to gently rock it back and forth while pulling upward. Do not twist or pry the relay, as this can damage the socket.

6. Install the New Relay
Align the prongs on the new relay with the slots in the socket. Push the relay straight down until it clicks into place. Make sure it is seated fully and securely.

7. Reconnect the Battery
Reconnect the negative battery terminal and tighten the clamp.

8. Test the System
Turn the key to the "ON" position and listen for the fuel pump prime sound. If you hear the pump run for about two seconds, the relay is working. Start the engine and let it idle. If the engine starts and runs smoothly, the repair is complete.

9. Replace the Fuse Box Cover
Snap the fuse box cover back into place to protect the electrical components from dirt and moisture.

When to Call a Professional

While replacing the fuel pump relay is a simple DIY job, some situations require professional help. If you have tested the relay, checked all the fuses, and verified that the wiring is intact, but the fuel pump still does not run, the problem may be more complex. The ECM itself can fail, or there may be a wiring fault deep in the harness that is difficult to trace without specialized equipment. Additionally, if the fuel pump shut off system has been triggered by a collision, the vehicle may need to be inspected for fuel leaks before restarting.

Also, if you smell fuel, see smoke, or notice any other signs of electrical burning, stop immediately and have the vehicle towed to a qualified mechanic. Electrical problems can quickly become dangerous if not handled properly.

KEMSO Fuel Pump: The Best Upgrade for Your 2002 Toyota Highlander

If you have diagnosed the fuel pump itself as the problem and need a replacement, look no further than KEMSO. KEMSO offers high-performance fuel pumps that are designed as direct OEM replacements for a wide range of vehicles, including the 2002 Toyota Highlander. Whether you have the 2.4L 4-cylinder engine or the 3.0L V6, KEMSO has a fuel pump that will fit perfectly and perform reliably.

What sets KEMSO apart from other brands is their commitment to quality and customer satisfaction. Every KEMSO fuel pump is built to meet or exceed original equipment specifications, ensuring a perfect fit and trouble-free operation. The pumps undergo rigorous testing to guarantee reliable fuel delivery under all driving conditions. And with a lifetime warranty backing every purchase, you can buy with complete confidence. KEMSO stands behind their products, promising that your fuel pump will perform for as long as you own your vehicle.

Visit the KEMSO website today to find the right fuel pump for your 2002 Toyota Highlander: https://www.kemsoracing.com/

Final Thoughts

The fuel pump relay on a 2002 Toyota Highlander is located in the engine compartment fuse box on the left side of the engine bay. It is a small, inexpensive part that can cause big problems when it fails. Before you spend time and money replacing the fuel pump itself, always check the relay first. Testing it takes only a few minutes with a multimeter, and replacing it is as simple as pulling out the old one and plugging in a new one.

Remember that the fuel pump relay works in conjunction with the EFI main relay, the ECM, and several fuses. If the relay is good, check the EFI fuse (20A), the AM2 fuse (30A), and the ECU-B fuse (7.5A). If everything checks out, the problem may be in the wiring, the fuel pump itself, or the ECM.

For a reliable, long-lasting fuel pump replacement, choose KEMSO. Their products are built to last, backed by a lifetime warranty, and designed to get your 2002 Toyota Highlander back on the road quickly. Visit https://www.kemsoracing.com/ to learn more and place your order.


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