2001 Honda Civic Fuel Pump Relay: Symptoms, Location, and Replacement Guide

If your 2001 Honda Civic cranks but won't start, stalls while driving, or you don't hear the fuel pump prime when you turn the key, the fuel pump relay is likely the culprit. The fuel pump relay is an electronic switch that controls power to the fuel pump. When it fails, the fuel pump doesn't receive electricity, so the engine gets no fuel . The relay is located under the dashboard on the driver's side, inside the fuse box, and is labeled as the "PGM-FI Main Relay" . Replacing it is a straightforward, low-cost fix that can save you a trip to the mechanic. The genuine OEM part number for the 2001 Honda Civic fuel pump relay is 39794-S5A-003, and it fits all submodels including 2-Door DX, EX, HX, LX and 4-Door DX, EX, GX, LX .

What the Fuel Pump Relay Does

The fuel pump relay works as a magnetic switch. When you turn the ignition key to the "ON" position, a small electric current flows to the relay's coil. This creates a magnetic field that closes the relay's contacts, allowing a stronger current to flow to the fuel pump . The fuel pump then pressurizes the fuel system so the engine can start. Once the engine is running, the relay typically shuts off, and the oil pressure-sending unit takes over powering the pump . When you turn the key off, the relay cuts power to the fuel pump to prevent it from running unnecessarily.

The relay serves two critical safety functions: it prevents the fuel pump from running when the engine is off (even if the key is left in the "ON" position), and it protects the fuel pump and wiring from electrical damage .

Symptoms of a Bad Fuel Pump Relay

A failing fuel pump relay can cause several distinct problems. Here are the most common signs:

1. Engine cranks but won't start. This is the most typical symptom. The starter motor turns the engine over, but because the fuel pump isn't getting power, no fuel reaches the engine . You may turn the key and hear the starter spin, but the engine never fires up.

2. Engine stalls while driving. If the relay fails while you're on the road, the fuel pump suddenly loses power, and the engine dies without warning. In some cases, the car may restart after sitting for a while once the relay cools down, but this is a sign the relay is on its way out .

3. No fuel pump priming noise. When you turn the key to the "ON" position (before cranking), you should hear a brief humming or whining sound from the rear of the car near the fuel tank. This is the fuel pump pressurizing the system. If you don't hear this sound, the relay may not be sending power to the pump .

4. Intermittent starting issues. Sometimes the car starts fine, other times it doesn't. This inconsistency often points to a relay with failing internal contacts or a loose connection .

5. Loss of power while driving. The car may suddenly lose power, hesitate, or sputter before recovering. This happens when the relay intermittently loses contact, causing the fuel pump to cut in and out .

Where to Find the Fuel Pump Relay on a 2001 Honda Civic

On the 2001 Honda Civic, the fuel pump relay is located under the dashboard on the driver's side. It's inside the interior fuse box, which is mounted near the driver's left knee . The relay is typically labeled as the "PGM-FI Main Relay" in the fuse box diagram. This relay controls both the fuel pump and the fuel injectors .

To access it:

• Sit in the driver's seat and look under the dashboard near the steering column.
• Locate the rectangular fuse box panel. It may have a cover that you can pull off by hand.
• The relay is a small, cube-shaped component with prongs that plug into the fuse box .
• If you're unsure which relay is the fuel pump relay, check the diagram printed on the inside of the fuse box cover.

How to Test the Fuel Pump Relay

Before buying a new relay, you can perform a quick test. Here's a simple method that doesn't require special tools:

The swap test: Find a relay of the same size and shape in the fuse box (such as the horn relay or a similar 5-pin relay). Swap it with the suspected fuel pump relay. If the car starts, the fuel pump relay was the problem .

The listening test: Have someone turn the key to the "ON" position while you listen near the fuse box. If you hear a distinct clicking sound from the relay, it's likely working. If you hear nothing, the relay may be dead .

The multimeter test: If you have a multimeter, you can check for power at the relay terminals. With the key in the "ON" position, you should see battery voltage on the input terminals. If power is present at the relay but not at the fuel pump, the relay is likely bad .

Replacement Options for the 2001 Honda Civic Fuel Pump Relay

OEM Honda Part: The genuine Honda fuel pump relay for the 2001 Civic is part number 39794-S5A-003 . This is a direct replacement manufactured by Mitsuba and weighs about 0.10 pounds. It's covered by Honda's factory warranty and fits all 2001 Civic submodels including 2-Door and 4-Door versions with automatic, manual, or CVT transmissions . The OEM part typically costs around $45 to $48 . This relay also fits many other Honda models including the 2001-2003 Civic hatchbacks, 2002-2006 CR-V, 2004-2009 S2000, and 2001-2005 Stream .

Aftermarket Options: Several aftermarket brands offer compatible relays. The Standard Ignition RY-726 is a widely available aftermarket replacement that fits the 2001-2007 Honda Civic, among other Honda models . Beck/Arnley also offers a compatible fuel pump relay (part 203-0129) for the 1998-2001 Civic 4-door sedan . These aftermarket options are generally less expensive than OEM parts.

Important: When ordering, always verify that the part number matches your vehicle's requirements. The 2001 Civic uses a 5-pin relay . Some older Honda models (1992-2000) use a different relay with part number 39400-SM4-003, which is not compatible with the 2001 model . Don't assume all Civic relays are the same—always confirm the part number.

How to Replace the Fuel Pump Relay

Replacing the fuel pump relay on a 2001 Honda Civic is a simple DIY job that takes about 10 minutes. No special tools are required.

Step 1: Open the driver's door and locate the interior fuse box under the dashboard near your left knee.

Step 2: Remove the fuse box cover. You may need to pull firmly—it's usually held on by plastic clips.

Step 3: Identify the PGM-FI Main Relay using the diagram on the fuse box cover. It's typically a square or rectangular relay with five prongs.

Step 4: Grip the relay firmly and pull straight up to remove it. If it's tight, you can use a small flathead screwdriver to gently pry it loose .

Step 5: Insert the new relay by pushing it straight down into the socket until it clicks into place.

Step 6: Replace the fuse box cover and test the car by turning the key to the "ON" position. You should hear the fuel pump prime for 2-3 seconds.

Why Your 2001 Civic Might Need a New Fuel Pump Relay

The fuel pump relay in the 2001 Honda Civic is a common failure point, especially as the vehicle ages. Over time, the internal contacts can wear out, develop corrosion, or fail due to heat cycling . The relay is located inside the cabin, so it's protected from weather, but it still experiences thousands of on-off cycles over the life of the car.

Some owners experience intermittent problems where the car starts fine for weeks, then suddenly refuses to start. This is often caused by a relay with failing internal contacts that work intermittently until they finally fail completely .

Recommended Upgrade: KEMSO Fuel Pump for Your Honda Civic

While the fuel pump relay is often the cause of starting problems, sometimes the fuel pump itself needs replacing. If you've already replaced the relay and your Civic still has fuel delivery issues, consider upgrading to a KEMSO Fuel Pump.

KEMSO is a leading US aftermarket fuel pump manufacturer that offers high-performance, OEM replacement fuel pumps for a wide range of vehicles, including Honda models . All KEMSO fuel pumps are designed to meet or exceed original equipment specifications, ensuring a perfect fit and reliable performance. Best of all, every KEMSO fuel pump comes with a lifetime warranty, giving you complete peace of mind .

Whether you need a fuel pump for your Honda Civic or any other vehicle, KEMSO has you covered. Their product line includes pumps for cars, motorcycles, ATVs, and UTVs. Visit the KEMSO website at https://www.kemsoracing.com/ to browse their full selection and find the right fuel pump for your vehicle.

Final Thoughts

The fuel pump relay is a small, inexpensive part that can cause big problems when it fails. If your 2001 Honda Civic won't start, stalls unexpectedly, or you don't hear the fuel pump prime, start by checking the relay. It's located under the driver's side dashboard in the fuse box and is labeled as the PGM-FI Main Relay . The genuine OEM part number is 39794-S5A-003 . Replacing it is a simple, 10-minute DIY job that can save you a tow truck bill and a trip to the shop.

For more information on fuel system components and replacement parts, visit https://www.kemsoracing.com/ to explore KEMSO's full line of high-quality fuel pumps backed by a lifetime warranty.