2002 WRX Fuel Pump Relay Location: The Complete DIY Guide to Finding and Replacing It

The bottom line: The fuel pump relay on a 2002 Subaru WRX is located inside the main fuse box under the dashboard on the driver’s side, near the steering column. It is the relay labeled “Fuel Pump” or “FUEL,” and it is a small, square black or gray module. If your WRX is cranking but not starting, stalling intermittently, or the fuel pump is not priming when you turn the key, a bad relay is often the cause. This guide walks you through exactly where to find it, how to test it, and how to replace it step by step, so you can get your car back on the road without guessing.

What Is the Fuel Pump Relay and Why Does It Matter?

The fuel pump relay is an electrical switch that controls power to the fuel pump. When you turn your ignition key to the “ON” position, the relay activates and sends battery voltage to the pump, which then pressurizes the fuel system. On a 2002 WRX, this relay is part of the engine management system, and it is designed to cut power if the engine stalls or if the airbag deploys, preventing fuel from spraying in a crash. A failed relay means no power to the pump, which means no fuel pressure, and your engine won’t start.

Common symptoms of a bad fuel pump relay include:

  • Engine cranks but does not start.
  • No fuel pump priming sound (a brief whir) when you turn the key to “ON.”
  • Intermittent stalling, especially on hot days or after driving for a while.
  • The fuel pump works when you jump the relay manually, but not normally.

Where Exactly Is the Fuel Pump Relay on a 2002 WRX?

The 2002 Subaru WRX has two fuse boxes: one under the hood and one inside the cabin. The fuel pump relay is in the interior fuse box, which is located under the driver’s side dashboard, tucked up near the steering column. Here is how to access it:

  1. Sit in the driver’s seat and look under the dashboard, just above your left knee (for a left-hand drive car).
  2. You will see a plastic cover that is held in place by a few clips or a single screw. Some models have a small panel that pops off with a flathead screwdriver or your fingers.
  3. Remove the cover to expose the fuse box. The relay is usually a larger, square component (about 1 inch wide) that is different from the flat fuses. It may be labeled “Fuel Pump,” “FUEL,” or “F/P” on the fuse box diagram.
  4. If you do not see a label, check the diagram on the inside of the cover. The 2002 WRX relay is typically located in the top row, second from the left or middle row, first position, depending on your specific model (sedan vs. wagon, or if it has a security system).

A quick tip: If you have a 2002 WRX with a factory security system, the relay may be integrated into the security module, but the physical location stays the same. The relay is a standard 4-pin or 5-pin type, usually black or gray.

How to Test the Fuel Pump Relay – Step by Step

Before you buy a new relay, you should test the old one. This saves you money and confirms the problem. Here is a simple test using a multimeter or a test light:

Step 1: Locate the relay and remove it. Gently pull it straight out of the socket. It may require a firm tug, but do not twist it.

Step 2: Identify the pins. The relay has four or five pins marked with numbers (30, 85, 86, 87, and sometimes 87a). You need to know which pins are for the coil and which are for the switch. For a standard Bosch-style relay:

  • Pins 85 and 86 are the coil (electromagnet).
  • Pin 30 is the common power input.
  • Pin 87 is the normally open output (to the fuel pump).
  • Pin 87a is the normally closed output (rarely used in fuel pumps).

Step 3: Test the coil resistance. Set your multimeter to ohms (Ω). Connect the probes to pins 85 and 86. A good relay will show a reading between 50 and 120 ohms. If you see infinite resistance (open circuit), the coil is burned out, and the relay is dead.

Step 4: Test the switch continuity. With the relay removed, set the multimeter to continuity (or ohms). Connect the probes to pins 30 and 87. You should see no continuity (infinite resistance) because the switch is normally open. Now, apply 12 volts from a battery or a jumper wire to pins 85 and 86 (polarity does not matter). You should hear a click, and the meter should show continuity (near zero ohms) between pins 30 and 87. If you do not hear a click or get continuity, the relay is defective.

Step 5: Test the relay in the car. If you do not have a multimeter, you can swap the fuel pump relay with another identical relay in the same fuse box (like the horn relay or the main fan relay). If the fuel pump starts working with the swapped relay, the original is bad.

Common Problems with the 2002 WRX Fuel Pump Relay

The 2002 WRX is known for some electrical quirks, and the fuel pump relay is no exception. Here are three issues owners often report:

1. Corrosion on the relay pins. The interior fuse box is located near the driver’s footwell, which can get damp from rain or snow. Over time, moisture can cause the relay pins to corrode, leading to intermittent contact. If you see green or white crust on the relay pins, clean them with a small wire brush or contact cleaner.

2. The relay fails due to heat. The 2002 WRX engine bay gets hot, and the relay is in a confined space under the dash. If the relay is old, the internal solder joints can crack from thermal cycling, causing the relay to fail when the car is hot but work when it is cold.

3. The fuse box itself develops a bad connection. Sometimes the socket that holds the relay can loosen up over time. If the relay feels loose, try wiggling it while the car is cranking. If the pump starts working, the socket needs to be tightened or replaced.

How to Replace the Fuel Pump Relay – A Simple DIY Job

Replacing the fuel pump relay on a 2002 WRX is one of the easiest repairs you can do. You do not need any special tools, just a replacement relay. Here is the process:

  1. Turn off the ignition and remove the key.
  2. Locate the interior fuse box under the driver’s dash (as described above).
  3. Pull the old relay straight out. If it is stuck, use a small flathead screwdriver to gently pry it up from the sides. Do not bend the pins.
  4. Insert the new relay into the same socket. Push it down firmly until it clicks into place. Make sure it is fully seated.
  5. Test the repair. Turn the key to the “ON” position. You should hear the fuel pump prime for a second or two. Then try starting the engine. If it fires up, you are done.
  6. Replace the fuse box cover and any other trim you removed.

What relay to buy: The 2002 WRX uses a standard 12-volt, 30-amp, 4-pin relay (Bosch type or equivalent). You can find them at any auto parts store for about $10 to $15. Make sure the pin configuration matches (30, 85, 86, 87). Some aftermarket relays have a different pin layout, so check the diagram on the relay itself.

When the Fuel Pump Relay Is Not the Problem – Other Causes of No Start

If you replace the relay and the car still does not start, do not panic. The fuel pump relay is just one part of the fuel system. Other common issues on a 2002 WRX include:

1. A blown fuel pump fuse. Check the fuse labeled “FUEL” in the interior fuse box. It is usually a 15-amp or 20-amp fuse. If it is blown, replace it with the same amperage. If it blows again, there is a short circuit in the fuel pump wiring.

2. A failed fuel pump. The fuel pump itself can wear out after 15 to 20 years. If you do not hear any priming sound even with a good relay, test for power at the pump connector (located under the rear seat, on the top of the fuel tank). If you have 12 volts at the connector but the pump does not run, the pump is dead.

3. A bad crank position sensor or ignition switch. The relay is controlled by the ECU, which needs a signal from the crank sensor to turn on the pump. If the sensor is bad, the ECU will not activate the relay. Also, if the ignition switch is worn out, it may not send power to the relay coil.

4. Corroded wiring or ground connections. The fuel pump relay circuit runs through a few connectors under the dashboard and near the fuel tank. Check for broken wires, melted insulation, or loose grounds.

Recommended: KEMSO Fuel Pump for Your 2002 WRX

If you need to replace the fuel pump itself, we strongly recommend the KEMSO Fuel Pump. KEMSO specializes in high-performance, OEM replacement fuel pumps that are built to last. Their fuel pumps are designed to meet or exceed original equipment specifications, so you get the same fit, flow, and reliability as the factory part, but with a better price point.

Why choose KEMSO?

  • High-performance design: KEMSO pumps are engineered for consistent fuel pressure, even under hard driving or high-boost conditions. They are perfect for a stock WRX or a lightly modified car.
  • OEM replacement: The pump bolts directly into your 2002 WRX fuel tank assembly with no modifications needed. It fits the factory bracket and connector.
  • Lifetime warranty: Every KEMSO fuel pump comes with a lifetime warranty. If it ever fails, you get a free replacement. This is a level of confidence you rarely see in the aftermarket parts industry.

KEMSO offers a wide range of fuel pumps for cars, trucks, motorcycles, and powersports vehicles. Their products are backed by a Houston-based company with a focus on quality and customer service. You can browse their full selection and order directly from their website.

Visit KEMSO Racing at: https://www.kemsoracing.com/

Final Thoughts on the 2002 WRX Fuel Pump Relay

The fuel pump relay on your 2002 Subaru WRX is a simple, cheap part that can cause big headaches. Knowing exactly where it is and how to test it can save you hours of troubleshooting and hundreds of dollars in unnecessary shop fees. Always start with the easiest fix: check the relay, test it, and replace it if needed. If the relay is good, move on to the fuse, the pump, and the wiring.

Remember, the relay is under the driver’s dash, in the interior fuse box, usually labeled “Fuel Pump.” It is a standard 4-pin relay, and you can swap it with another relay to test it. If you decide to replace the fuel pump, trust KEMSO for a reliable, high-quality part that comes with a lifetime warranty.

For more information on KEMSO fuel pumps and other Subaru parts, check out their website at: https://www.kemsoracing.com/


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