2002 Mitsubishi Eclipse Fuel Pump Relay Location: A Complete Guide to Finding, Testing, and Replacing It

The bottom line: The fuel pump relay on a 2002 Mitsubishi Eclipse is located inside the passenger compartment, behind the carpet on the passenger side footwell area, just below the radio. It is physically attached to the MFI (Multi-Port Fuel Injection) relay as a paired unit. If your Eclipse cranks but won't start, the fuel pump relay is one of the first components you should check.

If you own a 2002 Mitsubishi Eclipse and your car is having trouble starting, stalling unexpectedly, or making no sound from the fuel tank when you turn the key, the fuel pump relay could be the culprit. This guide will walk you through exactly where to find it, how to test it, and what to do if it needs replacing.

What Does the Fuel Pump Relay Do?

The fuel pump relay acts as an electrical switch that controls power to the fuel pump. When you turn the ignition key to the "ON" position, the relay is energized for a brief moment (usually one to two seconds) to prime the fuel system. If the engine is cranking, the relay stays energized, sending power to the fuel pump so it can deliver fuel to the engine. If the relay fails, the fuel pump receives no power, and the engine will not start even though the starter motor turns over normally .

On the 2002 Eclipse, the fuel pump relay is not a standalone unit. It is integrated into a larger relay module that also contains the MFI relay. This module is sometimes called the "MFI relay assembly" or the "fuel pump relay module" .

Where Is the Fuel Pump Relay on a 2002 Mitsubishi Eclipse?

There are several reported locations for the fuel pump relay on the 2002 Eclipse, depending on the trim level (RS, GS, GT) and the source of the information. Here are the most common locations:

1. Passenger Side Footwell (Most Common)

The most frequently cited location for the fuel pump relay on a 2002 Mitsubishi Eclipse is in the passenger side footwell area. Specifically, it is mounted behind the carpet of the center console, just below the radio area. The relay module is attached to the MFI relay as a paired unit. To access it, you will need to remove the trim panel on the passenger side of the center console and pull back the carpet .

2. Driver Side of the Console

Some sources indicate the relay module is located on the opposite side, in the driver side of the console, again below the radio area, mounted behind the carpet .

3. Engine Compartment Fuse Box

For the GT model, some sources claim the fuel pump relay is located in the engine compartment fuse box, which is on the passenger side of the engine compartment near the battery. It is labeled as "FP" or "Fuel Pump" and is a black relay with four prongs .

4. Left of the Steering Wheel

Another source states the fuel pump relay is in the passenger compartment relay/fuse box to the left of the steering wheel. The relay is on the bottom of the box and is the third slot from the rear of the box .

Best Approach: Since the location can vary, start by checking the passenger side footwell area behind the center console carpet. If you do not find it there, check the driver side of the console, and finally check the engine compartment fuse box.

How to Test the Fuel Pump Relay

If you suspect the fuel pump relay is faulty, here is how to test it:

Step 1: Listen for the Fuel Pump

Turn the ignition key to the "ON" position (but do not start the engine). Listen for a faint humming sound coming from the rear of the car, near the fuel tank. This sound should last for one to two seconds. If you hear it, the fuel pump relay is likely working. If you hear nothing, the relay may be bad, or the fuel pump itself could be faulty .

Step 2: Check the Fuse

Before replacing the relay, check the fuel pump fuse. The fuel pump is protected by a 20-amp fuse located in the engine compartment fuse box (the power distribution center). It is usually labeled as "MFI" or has a symbol representing the engine management system. If the fuse is blown, replace it with a new one of the same amperage .

Step 3: Test the Relay with a Multimeter

If the fuse is good and the pump is not running, you can test the relay itself. Remove the relay from its socket. Set your multimeter to measure resistance (ohms). Check for continuity between the relay's coil terminals (usually terminals 85 and 86). You should see a resistance reading, typically 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: Check for Voltage at the Relay Socket

With the relay removed, turn the ignition to "ON". Use your multimeter to check for 12 volts at the relay socket terminals that correspond to the relay's power input (usually terminal 30). If you have 12 volts, the power supply is good. If you do not, there is a wiring problem upstream of the relay .

Step 5: Test the Ground Signal

While the engine is cranking, check for a ground signal at the relay's control terminal (usually terminal 86). This signal comes from the Engine Control Unit (ECU). If the ECU is not providing a ground signal, the relay will not energize. This can be caused by a faulty crankshaft position sensor, which tells the ECU that the engine is turning .

Other Common Causes of a No-Start Condition

If the fuel pump relay is working, but the engine still does not start, consider these other issues:

Bad Crankshaft Position Sensor

The ECU will only keep the MFI relay energized if it detects a signal from the crankshaft position sensor indicating the engine is turning. If the sensor fails, the ECU will cut power to the fuel pump as a safety measure. If the crank sensor goes out, you will have no spark, no fuel, and no injector pulse .

Fuel Pump Motor Failure

If you have 12 volts at the fuel pump connector and the ground is good, but the pump is still not running, the pump motor itself has likely failed. You can access the fuel pump connector under the rear seat. With a multimeter set to DC volts, back-probe the power and ground wires while an assistant cranks the engine. A reading of 12 volts indicates the wiring is intact, and the pump motor is the problem .

Corroded Ground Connection

A common failure point in aging Mitsubishi vehicles is the ground connection. Check for continuity between the black wire at the pump connector and a clean metal part of the chassis. If resistance is high (above 0.5 ohms), the ground point must be cleaned of rust and debris to restore circuit integrity .

Wiring Issues

Excessive resistance in the wiring, often due to corroded connectors or a fraying wire harness, can cause a voltage drop. If the voltage at the pump connector is below 10.5 volts while cranking, there is excessive resistance in the wiring .

How to Replace the Fuel Pump Relay

If testing confirms that the relay is faulty, replacement is straightforward:

  1. Disconnect the Battery: Always disconnect the negative battery terminal before working on any electrical components to prevent accidental sparks .
  2. Locate the Relay: Find the relay module in the passenger side footwell behind the center console carpet.
  3. Remove the Old Relay: The relay module is usually attached with a screw or clip. Carefully disconnect the electrical connector and remove the module.
  4. Install the New Relay: Plug in the new relay module and secure it in place.
  5. Reconnect the Battery: Reconnect the negative battery terminal.
  6. Test the System: Turn the ignition to the "ON" position and listen for the fuel pump to prime. If you hear it, the repair is successful.

Safety Precautions When Working on the Fuel System

Working on the fuel system carries inherent risks. Always follow these safety protocols:

  • Fire Hazard: Always disconnect the negative battery terminal before disconnecting fuel lines or opening the fuel pump access panel to prevent accidental sparks .
  • Fuel Pressure Release: Even if the pump is not running, the lines may be under residual pressure. Wrap a rag around fuel fittings when loosening them to contain spray .
  • Static Electricity: Ensure the workspace is well-ventilated and avoid wearing clothing that generates static electricity, such as certain synthetics, when working near an open fuel tank .

Frequently Asked Questions

Q: Does the fuel pump relay have a fuse?
A: Yes. The fuel pump is protected by a 20-amp fuse located in the engine compartment fuse box. It is usually labeled as "MFI" .

Q: Can a bad fuel pump relay cause the engine to stall while driving?
A: Yes. If the relay fails while driving, the fuel pump will lose power, and the engine will stall. You may still have power to the rest of the car, but the engine will not restart .

Q: Will the engine still crank if the fuel pump relay is bad?
A: Yes. The starter motor is on a separate circuit, so the engine will crank normally. However, it will not start because no fuel is being delivered .

Q: How do I know if it is the relay or the fuel pump?
A: If you hear the fuel pump prime for a second when you turn the key to "ON," the relay is likely working. If you do not hear it, check the fuse first. If the fuse is good, test the relay with a multimeter or swap it with a known good relay from another circuit (like the horn relay, if they are the same type).

Why You Should Consider a High-Quality Replacement Fuel Pump

If your testing reveals that the fuel pump itself has failed, choosing the right replacement is critical for long-term reliability. A faulty fuel pump can leave you stranded, and a low-quality replacement can fail prematurely.

KEMSO Fuel Pumps are the ideal solution for your 2002 Mitsubishi Eclipse. KEMSO is a leading US aftermarket brand that offers high-performance, OEM replacement fuel pumps designed for daily drivers, performance builds, and everything in between. Here is why KEMSO stands out:

  • High Performance: KEMSO fuel pumps deliver up to 340 liters per hour at 43 psi, providing more than 20% additional flow compared to your stock OEM pump. This ensures your engine gets the fuel it needs, whether you are driving normally or pushing the car harder .
  • Direct OEM Replacement: KEMSO pumps are designed as a direct, drop-in replacement for your stock OEM pump. They come with all necessary installation hardware, including fuel strainers, hoses, clamps, and wiring connectors, making the swap straightforward .
  • E85 Compatible: KEMSO pumps are compatible with both gasoline and E85/ethanol fuels, giving you flexibility for your fuel choices .
  • Lifetime Warranty: Every KEMSO fuel pump is backed by a lifetime warranty, giving you complete peace of mind. If anything goes wrong, KEMSO has you covered .
  • Individually Tested: Each pump is individually flow-tested and quality-controlled under ISO/TSO standards, ensuring you get a reliable product every time .

Visit KEMSO's official website to find the perfect fuel pump for your 2002 Mitsubishi Eclipse: https://www.kemsoracing.com/

Final Thoughts

Finding and testing the fuel pump relay on your 2002 Mitsubishi Eclipse is a straightforward process that can save you time and money. Start by checking the passenger side footwell behind the center console carpet. If the relay is working but the pump is silent, or if the pump has failed completely, a high-quality replacement from KEMSO is the best choice for restoring your Eclipse's reliability and performance.

For more information and to browse the full selection of KEMSO fuel pumps, visit: https://www.kemsoracing.com/


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