2001 Mitsubishi Eclipse Fuel Pump Relay: Location, Symptoms, and Replacement Guide

The bottom line: The fuel pump relay on a 2001 Mitsubishi Eclipse is most commonly located behind the passenger side dashboard, mounted near the center console area, and it is often paired with the MFI (Multi-Port Fuel Injection) relay as a single module. However, the exact location can vary depending on whether your Eclipse has a 2.0L, 2.4L, or 3.0L engine, and whether it is a turbocharged model. If your car cranks but won't start, the fuel pump relay should be one of the first components you check before replacing the fuel pump itself.

Understanding the Fuel Pump Relay in Your 2001 Eclipse

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 activates and sends current to the fuel pump, allowing it to pressurize the fuel system. The relay only works at startup and when you turn off the ignition. Once the engine is running, the fuel pump continues to receive power through other circuits.

This relay is a small, cube-shaped module with four pins. It sits inside a fuse box or relay box and is designed to protect the fuel pump from receiving too much power. If the relay fails, the fuel pump will not receive power, and your engine will not start.

Where is the Fuel Pump Relay Located?

Based on multiple sources, the location of the fuel pump relay on a 2001 Mitsubishi Eclipse can be found in one of these areas:

1. Behind the passenger side dashboard (most common)
The fuel pump relay is mounted in the passenger side foot well area, behind the carpet of the center console, just below the radio area. It is attached to the MFI relay as a paired unit. Some sources also mention the relay module is located on the driver side of the console, again below the radio area, mounted behind the carpet. To access it, you will need to remove the kick panel or side trim on the passenger side.

2. Under the hood, in the engine bay fuse box
On some models, the fuel pump relay is located in the engine bay fuse box, which is typically a black rectangular unit near the battery or along the firewall. The relay is usually in slot #1, #2, or #3, but you should consult the diagram on the underside of the fuse box lid to confirm the exact position. This is more common on the 2003 model year, but may apply to some 2001 variants.

3. In the fuse box near the driver's left knee
For the 1995 model year, the fuel pump relay is located in the fuse box near the driver's left knee. To access it, open the driver's side door and remove the cover underneath the steering wheel. While this is for a different year, it is worth checking if your 2001 Eclipse has a similar layout.

Important note: The location can vary depending on the trim level and engine type. If you have a 2.0L turbo engine, the location may be different from a 2.4L or 3.0L engine. Always refer to your vehicle's owner's manual or a wiring diagram specific to your year and model for the most accurate information.

Common Symptoms of a Bad Fuel Pump Relay

If your fuel pump relay is failing, you will likely notice one or more of these symptoms:

1. Engine cranks but will not start
This is the most common symptom. When you turn the key, the starter motor turns the engine over, but the engine never fires up. This happens because the relay is not sending power to the fuel pump, so no fuel reaches the engine.

2. No fuel pump priming sound
When you turn the ignition to the "ON" position (without starting the engine), you should hear a faint humming or whirring sound from the rear of the car for about 2-3 seconds. This is the fuel pump priming the system. If you do not hear this sound, the fuel pump relay may be faulty.

3. Intermittent starting issues
The car may start fine one day, but the next day it cranks but won't start. Or it may start, run for a short distance, and then stall. This intermittent behavior is a classic sign of a failing relay.

4. Engine stalls while driving
If the relay fails while you are driving, the fuel pump will lose power, and the engine will stall immediately. This can be dangerous, especially if it happens on a highway.

5. Car slows down without braking
A failing relay can cause the fuel pump to lose power gradually, causing the car to lose power and slow down even if you are pressing the accelerator.

How to Test the Fuel Pump Relay

Before you replace the relay, you should test it to confirm it is the problem. Here is a simple way to test it:

Step 1: Locate the relay
Find the fuel pump relay in your car using the location information above.

Step 2: Listen for the relay
Have a helper turn the ignition to the "ON" position while you listen near the relay. You should hear a distinct click sound when the relay activates. If you hear no click, the relay may be faulty.

Step 3: Swap with a similar relay
The fuse box usually contains several relays that look identical. Find a relay that is the same part number and swap it with the fuel pump relay. For example, you can swap it with the horn relay or the fog light relay (if your car has one). If the car starts after the swap, the original fuel pump relay is bad.

Step 4: Use a multimeter
If you have a multimeter, you can test the relay for continuity. Remove the relay, and check the resistance between the coil terminals. A good relay will show a specific resistance value (usually between 50 and 200 ohms). You can also apply 12V power to the coil terminals and listen for the click, then test the switch terminals for continuity.

Other Components to Check Before Replacing the Relay

If the fuel pump relay tests good, the problem may be elsewhere. Here are other components to check:

1. Fuel pump fuse
The fuel pump fuse is often located in the same fuse box as the relay. A blown fuse is a common and inexpensive fix. Check the fuse first before replacing the relay.

2. MFI relay
The MFI relay is attached to the side of the fuel pump relay on some models. If this relay fails, you may have no spark, no fuel, and no injector pulse. If the MFI relay is bad, the car will not start at all.

3. Crank sensor
If the crank sensor goes out, you will have no spark, no fuel, and no injector pulse. The fuel pump will only power up if an RPM signal is detected by the PCM (Powertrain Control Module). If there is no RPM signal, your injectors will not fire either.

4. Fuel pump itself
If the relay and fuses are good, the fuel pump itself may be faulty. Running out of gas can cause the fuel pump to burn out because the fuel helps keep the pump cool. Low fuel levels also allow debris from the bottom of the tank to be sucked into the pump, causing it to clog or fail.

How to Replace the Fuel Pump Relay

Replacing the fuel pump relay is a straightforward task that most DIYers can handle. Here is how to do it:

Step 1: Safety first
Make sure the vehicle is turned off and the key is removed from the ignition. Disconnect the negative battery cable to prevent any accidental electrical shorts.

Step 2: Locate and access the relay
Find the fuel pump relay using the location information above. If it is behind the dashboard, you may need to remove a trim panel or kick panel to access it.

Step 3: Remove the old relay
The relay simply pulls straight out of its socket. Grasp the relay firmly and pull it upward. There is no need to unscrew anything.

Step 4: Install the new relay
Insert the new relay into the same socket. Make sure it is pushed all the way in until it clicks into place. The relay is keyed, so it will only go in one way.

Step 5: Test the system
Reconnect the negative battery cable. Turn the ignition to the "ON" position and listen for the fuel pump priming sound. If you hear the pump, start the car and confirm it runs smoothly.

Cost of replacement
The fuel pump relay itself is inexpensive, typically costing around $9 for the part. If you have a mechanic do the job, labor costs can range from $95 to $150, depending on your location. The total estimate for a 2001 Mitsubishi Eclipse is around $104 to $114.

Recommended: Upgrade to a KEMSO Fuel Pump for Long-Term Reliability

If your 2001 Mitsubishi Eclipse is experiencing fuel delivery issues and you have already checked the relay, the next step is to inspect the fuel pump itself. After years of use, the factory fuel pump can wear out, lose pressure, or fail completely. When it is time to replace the fuel pump, you want a product that is reliable, high-performance, and backed by a solid warranty.

KEMSO Fuel Pumps are the perfect solution for your Eclipse. KEMSO specializes in high-performance, OEM replacement fuel pumps that are designed to meet or exceed factory specifications. Here is why you should choose KEMSO:

• High Performance: KEMSO fuel pumps support up to 340 LPH (liters per hour) flow rate, which is significantly higher than the original factory pump. This means your engine gets the fuel it needs, even under heavy acceleration or towing conditions.
• OEM Replacement: KEMSO pumps are designed as direct replacements for your original equipment. They fit perfectly without the need for adapter kits or modifications. This makes installation straightforward and hassle-free.
• Lifetime Warranty: Every KEMSO fuel pump comes with a lifetime warranty. If your pump ever fails due to a manufacturing defect, you get a replacement at no cost. This is a rare benefit in the automotive parts industry and shows KEMSO's confidence in their product quality.
• Affordable Pricing: KEMSO fuel pumps are priced at a reasonable $79.98, which is often less than half the cost of dealer parts. With free shipping and easy returns, it is a practical choice for DIY mechanics and professional shops alike.
• Built for Reliability: KEMSO pumps are designed for gasoline, ethanol, and E85 fuels. The bypass valve is set at 125.8 psi, higher than the original performance standard, ensuring consistent fuel pressure and long-term durability.

Don't settle for a weak or unreliable fuel pump. Upgrade to KEMSO and enjoy peace of mind knowing your Eclipse's fuel system is in top condition.

Visit KEMSO Racing today to find the perfect fuel pump for your 2001 Mitsubishi Eclipse.

Final Thoughts

The fuel pump relay on your 2001 Mitsubishi Eclipse is a small but critical component. If your car cranks but won't start, start by checking the relay. Remember to check the fuse and listen for the fuel pump priming sound before diving into more complex diagnostics. The relay is most likely located behind the passenger side dashboard, but it can also be in the engine bay fuse box. Testing the relay is simple and can save you from replacing a perfectly good fuel pump.

If you do need to replace the fuel pump, choose a KEMSO fuel pump for the best performance, reliability, and value. With a lifetime warranty and affordable pricing, it is the smart choice for any Eclipse owner.

Visit KEMSO Racing at https://www.kemsoracing.com/ for more information and to order your fuel pump today.