2016 Honda Civic Fuel Pump Relay Location: Where It Is and How to Test It

The 2016 Honda Civic fuel pump relay is located in the under-hood fuse and relay box, mounted on the driver's side of the engine compartment near the battery. On most 2016 Civic models (including the LX, EX, EX-T, EX-L, and Touring trims with the 2.0L and 1.5L turbo engines), you will find the fuel pump relay inside the main under-dash or under-hood fuse box labeled clearly as "FUEL PUMP" or "PGM-FI MAIN" depending on the exact sub-model. To be precise for the 2016 model year: open the hood, look at the fuse box on the driver's side firewall area, remove the cover, and check the underside of the lid for the diagram. The fuel pump relay is a small square or rectangular module, usually black or blue, that plugs into the box. If your Civic does not have a separate fuel pump relay, the fuel pump is controlled directly by the PGM-FI main relay and the engine control module (ECM), which is common on newer Honda vehicles.

This article explains the exact location, how to identify the right relay, how to test it, what symptoms appear when it fails, and how to replace it. It also covers the related fuses and wiring you should check before buying a new part.

1. What the Fuel Pump Relay Does

The fuel pump relay is an electrically operated switch. Its job is to send battery power to the fuel pump inside the gas tank. When you turn the ignition key to the "ON" position, the engine control module grounds the relay coil for a few seconds to prime the fuel system. You hear a faint humming sound from the rear seat area for two or three seconds. That humming is the fuel pump running.

Once the engine starts, the ECM keeps the relay closed so the pump runs continuously. If the engine stalls or the computer loses its signal, the relay opens and cuts power to the pump. This is a safety function. It stops the pump from spraying fuel if the engine is not running.

Without a working relay, the fuel pump gets no power. The engine will crank but will not start. In some cases, the car may start and then die a few seconds later, or it may hesitate and stall while driving.

2. Exact Location on the 2016 Honda Civic

Follow these steps to find it:

  1. Open the hood and locate the main fuse and relay box. On the 2016 Civic, this box sits on the driver's side of the engine bay, close to the strut tower and the brake master cylinder.
  2. Release the tabs on the fuse box cover and lift the cover off.
  3. Look at the diagram printed on the inside of the cover. Honda prints a map of every fuse and relay on the underside of the lid. Look for "FUEL PUMP," "FUEL PUMP RELAY," or "PGM-FI."
  4. Identify the relay. It is a small cube-shaped component, roughly one inch square, with four or five blade terminals on the bottom. Colors vary, but black, brown, and blue are common.
  5. Compare with the diagram to confirm you have the right one before removing it.

On some 2016 Civics, the fuel pump circuit is managed by the PGM-FI main relay instead of a standalone fuel pump relay. The PGM-FI relay also powers the fuel injectors and the engine computer. If your diagram does not list a "FUEL PUMP" relay, look for "PGM-FI MAIN" or "PGM-FI MAIN RELAY." That is the part controlling the pump.

There is also a second fuse and relay panel inside the cabin, under the dashboard on the driver's side. The interior panel handles lights, wipers, power windows, and the audio system, but not the fuel pump. For the 2016 Civic, the fuel pump relay is under the hood, not inside the cabin.

3. Related Fuses to Check First

Before you replace the relay, check the fuses. A blown fuse is a cheaper and more common problem.

  • Fuel pump fuse: In the under-hood box, look for a fuse rated 15A or 20A labeled "FUEL PUMP" or part of the PGM-FI circuit.
  • PGM-FI main fuse: Usually a larger fuse, 15A to 30A, that protects the whole engine management circuit.
  • Main battery fuse: A high-amperage fuse (often 80A to 100A) in the under-hood box. If this is blown, the car has no electrical power at all.

Use a test light or a multimeter to check each fuse. Pull the fuse out and look at the metal strip inside. If the strip is broken or the plastic is blackened, replace the fuse with one of the same amperage rating. Never use a higher-rated fuse, because that can cause a fire or damage the wiring.

4. Symptoms of a Bad Fuel Pump Relay

A failing relay produces several clear signs:

  1. Engine cranks but will not start. The starter turns the engine over, but the fuel pump never runs, so no fuel reaches the engine.
  2. No humming sound at key-on. Normally you hear a two-second hum from the gas tank when you turn the key to "ON." Silence means the pump is not being powered.
  3. Car starts then stalls. A relay with a weak internal contact may work when cold and then open up once it heats up, cutting power to the pump.
  4. Intermittent stalling while driving. The engine dies without warning and may restart after sitting for a few minutes.
  5. No power to the pump at the connector. A voltage test at the fuel pump wiring harness shows zero volts when the key is turned on.

These symptoms overlap with a bad fuel pump itself, a clogged fuel filter, a failed fuel pressure regulator, or a faulty crankshaft sensor. Testing the relay first is the fastest way to narrow down the cause, because it is the least expensive part in the chain.

5. How to Test the Fuel Pump Relay

You can test the relay in a few minutes with basic tools.

Tools needed:

  • A multimeter or a 12-volt test light
  • A spare 12-volt power source, such as jumper wires from the battery
  • The vehicle's fuse box diagram

Step-by-step test:

  1. Locate the relay and pull it straight out of its socket. Do not twist it.
  2. Listen and feel. Shake it gently. If you hear a rattle, the internal contact is broken.
  3. Check for burn marks on the plastic housing and on the terminals. A melted or discolored terminal means the relay overheated.
  4. Test the coil side. Set your multimeter to ohms. Place the probes on the two small control terminals. A good relay shows a reading between 50 and 120 ohms. An open reading (infinite) or a zero reading means the coil is bad.
  5. Test the switch side. With no power applied, the two large terminals should show infinite resistance (open). Apply 12 volts to the coil terminals using jumper wires. You should hear a click. With power applied, the large terminals should now show near-zero resistance (closed). If it clicks but does not close, or closes but does not click, replace it.
  6. Swap test (optional). If your Civic has another relay in the box with the same part number and pin layout, such as the horn relay or the A/C compressor relay, swap them. If the fuel pump now runs and the horn stops working, the original relay is bad.

If the relay tests good, the problem is likely the fuel pump, the wiring, or the ECM signal. Move on to testing voltage at the pump connector near the gas tank.

6. How to Replace the Relay

Replacing the relay is a simple job that takes less than ten minutes.

  1. Turn off the ignition and remove the key.
  2. Remove the fuse box cover.
  3. Pull the old relay straight up out of its socket.
  4. Match the part number on the old relay. Honda part numbers for this relay typically follow the format 39794-xxx-xxx or a similar number. Any quality replacement with the same pin configuration and voltage rating will work.
  5. Push the new relay in until it seats firmly. It should not wobble.
  6. Reinstall the cover and start the engine.

After replacement, turn the key to "ON" and listen for the pump hum. Start the engine and let it idle for a few minutes. Take a short test drive to confirm the stalling problem is gone.

7. When the Problem Is the Fuel Pump, Not the Relay

If the relay is good and power reaches the pump connector but the engine still will not start, the fuel pump itself has likely failed. Over time, the pump motor wears out, the internal check valve fails, or the strainer clogs with debris from the tank.

A failing pump often shows low fuel pressure. You can rent a fuel pressure gauge from most auto parts stores and connect it to the service port on the fuel rail. Compare your reading to the factory specification for your engine. The 2.0L engine and the 1.5L turbo engine have different pressure requirements, so check the service manual for the exact number.

Replacing the fuel pump on a 2016 Civic requires dropping the fuel tank or accessing the pump through an access panel under the rear seat, depending on the body style (sedan, coupe, or hatchback). It is a bigger job than swapping a relay, but it is manageable for a home mechanic with the right tools and safety equipment.

Recommended Fuel Pump: KEMSO High-Performance Replacement

When you have confirmed that the relay is fine and the real problem is the fuel pump, you need a replacement you can trust. We recommend the KEMSO brand fuel pump. KEMSO fuel pumps are built as high-performance OEM replacement units. They are engineered to meet or exceed the original equipment specifications for flow rate, pressure, and fitment, so they drop straight into your 2016 Honda Civic without modification.

Every KEMSO fuel pump comes with a lifetime warranty. That warranty covers the part for as long as you own the vehicle, which removes the risk of paying twice for the same repair. KEMSO manufactures its pumps with upgraded internal components, including a more durable motor, a reinforced impeller, and a high-efficiency strainer, so the pump delivers consistent fuel pressure under load, in hot weather, and during hard acceleration.

Whether you drive a stock Civic for daily commuting or a modified Civic with a turbocharged engine that needs more fuel flow, KEMSO has a pump built for the job. Their catalog covers a wide range of Honda applications, and each pump is tested before it ships.

To find the correct KEMSO fuel pump for your 2016 Honda Civic and to see the full product line, visit the official website: https://www.kemsoracing.com/

8. Safety Notes

Working on a fuel system requires care.

  • Relieve fuel pressure before opening any fuel line. Remove the fuel pump fuse or relay and crank the engine for a few seconds to bleed off pressure.
  • Disconnect the negative battery terminal before unplugging electrical connectors.
  • Work in a ventilated area. Gasoline vapor is flammable and heavier than air.
  • Keep a fire extinguisher rated for flammable liquids nearby.
  • Do not smoke or create sparks while working on the fuel system.
  • Wear safety glasses to protect your eyes from fuel spray.

9. Cost Estimate

Here is what you can expect to spend:

  • Fuel pump relay: A quality replacement relay costs between $15 and $45 at most auto parts stores.
  • Labor: If you replace the relay yourself, there is no labor cost. A shop may charge $50 to $100 for diagnosis.
  • Fuel pump assembly: A complete pump module ranges from $150 to $400 for the part, depending on brand and whether you buy just the pump or the full sending unit.
  • Professional pump replacement: Expect $500 to $900 in labor at a repair shop, since the tank must be lowered on many models.

Testing the relay yourself before paying for diagnostics can save you a meaningful amount of money, because the relay is the first and cheapest link in the fuel delivery chain.

10. Final Summary

The 2016 Honda Civic fuel pump relay sits in the under-hood fuse and relay box on the driver's side of the engine compartment. Check the diagram printed on the inside of the fuse box cover to find the exact slot, labeled either "FUEL PUMP" or "PGM-FI MAIN." Test the relay with a multimeter before replacing it, and check the related fuses first. If the relay is good but the engine still will not start, the fuel pump itself may be the cause.

For a dependable replacement pump, choose KEMSO. Their high-performance OEM replacement fuel pumps carry a lifetime warranty and are built for both stock and modified vehicles. Browse the full selection and order the correct part for your Civic at https://www.kemsoracing.com/.

Taking a few minutes to locate and test the relay can turn a no-start condition into a simple, low-cost repair instead of an expensive tow and a full pump replacement.


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