Bad Fuel Pump Relay Symptoms

Your automobile is stalling, idling, and displaying warning indications if it won’t start. Well, these are a few bad fuel pump relay symptoms. An essential part of your car’s fuel system is the fuel pump relay. When it’s time to increase fuel pressure in the rail, the fuel pump relay supplies electricity to the fuel pump. The gasoline pump relay is activated each time you turn on your car’s ignition.fuel pump relay symptoms

Well, in this article, we’ll have a closer look at bad fuel pump relay symptoms you’ll undoubtedly notice when there is one in your car. That said, the following questions will be addressed:

  • What is a Fuel Pump Relay?
  • Why Does Fuel Pump Relay Go Bad?
  • Where is it Located?
  • How Much Does Fuel Pump Relay Replacement Cost?

So, let’s get started!


What is a Fuel Pump Relay?

The fuel pump relay must have something to do with fuel, as is obvious from the name. To be accurate, the fuel pump is controlled by the fuel pump relay. An adequate amount of fuel is needed for a vehicle to operate properly. Fuel is fed to the combustion chamber through the gasoline tank when you start the car.

However, during this journey, the gasoline must pass through multiple different parts. The fuel pump relay’s responsibility is to provide a voltage signal and provide current to the fuel pump. in order to pressurize the fuel system and ensure that the proper amount of gasoline is delivered to the injectors.

This fuel will then be sprayed into the combustion chamber by the injectors. Controlling the fuel pump’s current supply is necessary because the fuel pump is an electrical component. You can only guarantee its smooth operation after that.

Why Does Fuel Pump Relay Go Bad?

Although a fuel pump relay can technically malfunction due to a short or another electrical issue, age is typically to blame for a damaged or broken fuel pump relay. The relay degrades slightly with each click, and after 100,000, 150,000, or even 200,000 kilometers, it adds up to quite a few clicks.

One day, it will simply be too much for it to handle, and it won’t click over or back to its previous position. It’s entirely normal, and aside from changing the relay, there’s nothing else you need to do as long as it doesn’t happen repeatedly.

What are the bad fuel pump relay symptoms?

The following are the most common fuel pump relay symptoms you’ll likely notice when you’ve got a bad one in your car:

  • Engine Stalls & Rough Idling
  • Your vehicle Won’t Start
  • The Check Engine Light
  • Engine performance issues
  • Faulty fuel pump
  • Fluctuating fuel consumption
  • A damaged fuel pump relay
  • Exhaust System Problems
  • Noiseless fuel pump

Engine Stalls & Rough Idling

Your automobile may stall out or idle rough due to a bad pump relay. An inadequate fuel supply will result from a malfunctioning fuel pump relay. In this case, you will hear gruff sounds emanating from the engine when your automobile is idling on a signal or otherwise. It seems as though the engine isn’t getting enough fuel.

Similar to when the fuel pump relay is malfunctioning, engine stalling will occur. The car will suddenly lose power when you are driving down the interstate at a high rate of speed. You would sense that the engine was no longer operating. A gasoline supply interruption is the cause of it. This cut-off was started by a malfunctioning relay.

Your vehicle Won’t Start

Relays for the fuel pump are also in charge of starting your car. When a gasoline pump relay malfunctions, your car will have trouble starting. Many of your car’s systems are engaged when you flip the ignition key. One of them is the fuel delivery system. The most important part of starting your car is the fuel pump pressurizing the fuel system.

And everyone is aware that a gasoline pump relay is located on the pump’s back. Without a gasoline pump relay that is in excellent condition, you can never have a fuel pump that is operating as it should. The fuel delivery system is pressurized by the fuel pump, and the pressurized gasoline will eventually reach the injectors.

The engine cycle is then completed by spraying it from this point into the combustion chamber. Thus, be sure to inspect your fuel delivery system if you experience any trouble starting your automobile. the fuel pump relay, which is very crucial.

The Check Engine Light

The check engine light (CEL) turning on is the earliest and most important warning that an electrical system component has failed. The electronic control unit, or ECU, of the car, sometimes known as the vehicle’s brain, is connected to almost all of the electrical system’s components.

Each of these parts sends signals to the ECU, which then divides up the instructions based on the inputs from various sensors. The ECU will be instantly aware of any relay that is broken or fails. The ECU will also turn on the check engine light on your dashboard as its initial action. You would be able to tell that a part of your car has failed in this way.

CEL is not, in my opinion, the best symptom to identify any auto defect. The reason is that the CEL can illuminate due to around 50 distinct issues. To identify the problem, you must still watch out for further signs of a defective component. You cannot ignore the check engine light, though. as it is right in front of you!

Engine performance issues

An automobile’s engine is powered by a mixture of fuel and air. The air-fuel ratio in a gasoline engine is fixed. The engine’s ability to operate properly is jeopardized if this ratio is altered. various outcomes would result from various fuel supplies, and vice versa. The fuel pump relay makes sure the fuel pump receives enough current.

Which will subsequently supply the injectors with the appropriate amount of fuel. If the relay malfunctions for any reason, there’s a risk that the pump isn’t getting the necessary current flow. The fuel delivery to the injectors is therefore impaired as a result. Poor engine performance would result from a lower fuel supply.

Faulty fuel pump

A fuel pump’s primary function is to pressurize and distribute fuel from the gas tank to the fuel injectors as needed. A fuel pump has a lifespan of roughly 100,000 miles on average. However, a defective fuel pump relay may result in failure much earlier. Therefore, you must inspect the relay as well if your fuel pump has failed and you are thinking about replacing it. A defective relay may overload the pump with current, leading to failure. Be on the lookout for this sign!

Fluctuating fuel consumption

When the pump relay malfunctions, your car’s fuel economy changes. Too much or too little fuel may be injected into the combustion chamber by a malfunctioning relay. This would imply that your engine will occasionally run rich and occasionally lean. As a result, inconsistent fuel usage in your car is a sign that the fuel pump relay has failed.

A damaged fuel pump relay

The most obvious sign of a malfunctioning fuel pump relay is this. The pump relay may have burned due to an excessive power supply. When performing routine car maintenance, you must visually verify the fuel relay if you notice any other symptoms of a damaged relay. You need to test it if the area surrounding it shows signs of burning.

Exhaust System Problems

We have talked about the effects of a lack of fuel. However, a faulty pump relay may potentially give more fuel than necessary. Only a small amount of fuel is intended to be burned in the engine’s combustion chamber.

At the end of the engine cycle, if more fuel entered the combustion chamber, it would remain unburned. An automobile’s exhaust system is used to collect combustion gases. Any additional product can clog your car’s exhaust system, including unburned petrol.

As a result, you should check your car’s fuel delivery system if you see unburned fuel in the muffler and you frequently experience exhaust system problems. Have a pump relay inspection performed on your car.

Noiseless fuel pump

The noise made by a car’s fuel pump indicates that it is working. The fuel pump is required to carry out the crucial role of pressurizing the fuel delivery system, particularly while you are starting the car. As a result, it pumps fuel under greater pressure. More noise is produced as a result, and you must hear it.

The correct current does not, however, reach the pump in the event of a malfunctioning fuel pump relay. It won’t work to its full potential as a result. As a result, the fuel pump will operate quietly, and you won’t hear it while the automobile is starting or accelerating. It is important to go to an auto repair shop if you notice that the automobile has gotten unusually quiet and you cannot hear the sounds of the pump.


Where is it Located?

A car’s fuel pump relay is like other fuses. Usually, the fuse box is where you can find it. Depending on your car’s make and model, the fuse box may be in one of two places. It might be near the firewall on the underside of the hood. Or it can be beneath the dashboard on the passenger side of your vehicle. You’re looking for a black box with possibly a plastic lid. When you open this box, a new universe of fuses, relays, and switches will be revealed.

How Much Does Fuel Pump Relay Replacement Cost?

The fuel pump relay typically costs between $45 and $165 to replace. It costs not too much to buy a fuel pump relay. For $20 to $50, you can purchase it at any typical auto store. For the replacement of the fuel pump relay, the total labor cost ranges from $25 to $120. The replacement of the pump relay is an easy task. It is as easy as switching.

You just purchase a new fuel pump relay from any auto supply store, find the fuel pump relay in your car’s fuse box using the wiring diagram, remove the old relay, and install the new one. In terms of labor, mechanics typically bill extra for this five-minute task. Even if you drive a fancy car, the cost would increase. The fuel pump relay replacement should definitely be attempted by you!

Related Article

How to bypass a bad fuel pump relay


What happens when the fuel pump relay goes bad?

The fuel pump won’t have power if the fuel pump relay malfunctions. Even though the engine may still turn over when the key is turned, it won’t be able to start because of a fuel shortage. It is strongly advised to have the vehicle carefully diagnosed because this symptom can also be brought on by a wide range of other problems.

What are the symptoms of a bad relay?

The fuel pump and ignition system will lose power if the relay malfunctions, which will cause no power and, consequently, no start. The accessories and maybe the engine can be turned on by turning the key.

What is the fuel pump relay responsible for?

In order to get fuel to your engine for combustion, the fuel pump relay is crucial. The primary job of the fuel pump relay is to supply the fuel pump with sufficient power, which is powered by the ignition and/or powertrain control module (PCM). The fuel pump cannot operate if the fuel pump relay is not functioning.

What causes the fuel pump to not kick on?

A broken fuel pump relay or control module, a blown fuse, a wiring error, a loose or corroded wire connector at the pump, or even a problem with the anti-theft system are examples of these. The fuel pump should be changed last after all other potential causes have been investigated and ruled out.

Can you start a car without a fuel pump relay?

Fuel pump failure results in no fuel pump. No fuel pump means no fuel. No fuel means no start.

How does a car act when the fuel pump relay is going out?

An engine that cranks but won’t start is the most typical symptom of a damaged fuel pump relay. Usually, a fuel pump relay will malfunction in the open position, cutting off power to the fuel pump. The engine will consequently run out of fuel and stop working.

Is it possible to bypass the fuel pump relay?

The simplest approach to disable your fuel pump relay is using a single jumper wire. Find the relay and unhook it from the socket immediately. By placing one end of the single jumper wire into one of the sockets and the other end into the other socket, you can replace it. Recharge the battery, then start the vehicle.

Final Words

One of your car’s most crucial systems is the fuel delivery system. For your engine to run at its best, it must be running properly. At the top of the gasoline delivery system is the fuel pump relay. It guarantees that the appropriate volume of fuel gets from the fuel tank to the injectors.

The fuel pump relay is essentially the fuel pump’s brain. The car’s ECU sends a signal that causes the fuel pump to turn on and supply the necessary amount of fuel after producing a current signal in response. There are several additional signs of a bad fuel pump relay. Top of the list are vehicle performance issues, rough idling, and engine stalling.

Additionally, a gasoline pump relay is essential for starting your car. Also, keep an eye out for it. Delivering too much fuel to the combustion chamber could result in the production of dangerous combustion gases. As a result, you must act quickly and have the fuel pump relay replaced if you notice any additional symptoms.

That is all for this article, where we took an in-depth look at the most common bad fuel pump relay symptoms. Even so, we addressed the following questions:

  • What is a Fuel Pump Relay?
  • Why Does Fuel Pump Relay Go Bad?
  • Where is it Located?
  • How Much Does Fuel Pump Relay Replacement Cost?

Hope it was helpful. If so, kindly share it with others. Thanks for reading, see you around!

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