Last Updated on 3 months by Ollie Barker
When you see your car check engine light is on, there is something wrong that needs attention. A failing fuel pump can be the reason for this. So, will bad fuel pump cause check engine light?
A bad fuel pump can result in a check engine light, but it does not always cause the engine to shut off. The good news is that you usually won’t need a new one unless the problem persists for more than a few days consistently.
What’s Car Fuel Pump?
A car fuel pump is a mechanical or electrical device that pumps gasoline or diesel fuel from the fuel tank to the engine of a car. The fuel pump pressurizes the fuel and sends it through the fuel lines to the engine, where it is mixed with air and burned to provide the energy needed to power the vehicle.
In modern cars, the fuel pump is typically located inside the fuel tank and is powered by electricity. Without a properly functioning fuel pump, a car cannot run.
What’s the Check Engine Light?
The check engine light is a warning indicator that is present on the dashboard of a car. It is also known as the malfunction indicator lamp (MIL) or service engine soon (SES) light. When the check engine light illuminates, it is an indication that there is a problem with one or more of the systems or components that are being monitored by the car’s onboard diagnostic system (OBD).
This could include issues with the engine, transmission, emissions, or other systems. The OBD system stores diagnostic trouble codes (DTCs) which can be read by a mechanic or with a specialized tool to help identify the problem.
It is important to address any issues indicated by the check engine light in a timely manner to prevent further damage to the vehicle and ensure it is running efficiently.
Will bad fuel pump cause check engine light?
A weak fuel pump can trigger the engine control module to turn on the check engine light. Also, any pump electrical issues can cause the check engine light on as well.
Fuel pumps are important and should not be neglected. Most fuel pumps do have a life longer than the vehicle, but they can also be prone to failure. If the fuel pump fails, you’ll need to take it out of the equation, or else your car will continue to stay in check engine mode.
Symptoms of a bad fuel pump
If your fuel pump is going bad, you may need to know how to troubleshoot it. Here are some symptoms that you can look for:
#1 Unusual noise
Whining noise is one of the common symptoms that mean a bad fuel pump. Whining noise may be heard from the fuel tank when you start your car or turn the engine off.
In addition, when the fuel pump has gone bad, it will make loud rattling noise from the tank which may be a little difficult to diagnose. A loud rattling noise can also be caused by clogged filters and even dirty injectors, but a bad fuel pump is still considered as the first cause to check.
#2 Engine stalls
If the fuel pump has gone bad, it can cause the engine to stall. Whether it’s a light or heavy stall, you should take your vehicle to a repair shop to check for damage and to confirm if it’s a bad fuel pump. There are some other things that can cause stalling as well, but they’re rarer than this one.
Engine stalling usually happens at a high temperature, and you can see it on your car thermometer. Again, this happens because the fuel pump is getting worse and it sets off the check engine light.
If the fuel pump has gone bad, it can cause hesitation in your vehicle. This hesitation is caused by low fuel pressure and can be caused by a bad fuel pump. You can check the engine while it’s running to see if the engine has any hesitation.
#4 Surge when accelerating
Another symptom of a bad fuel pump is if you feel a sudden surge when you accelerate. The gas pedal feels like it has been pressed down. Drivers can experience this more often when they’re on the highway.
#5 Loss of power
With a failing fuel pump, a vehicle is at a loss of power, especially when it’s under heavy loss or going uphill. To check this, you can accelerate a few times, and if you feel more power when your fuel pump is in good condition, then there is something wrong.
#6 Low gas mileage
If you notice that your gas mileage is suddenly lower, it could be an indication that the fuel pump is failing. The reason is that a valve in the fuel pump system might not work properly, either not opening or opening at the wrong time.
Will a bad fuel pump throw a code?
A code may indicate a problem with the fuel system or other systems in your vehicle. You’ll need to have a technician run a diagnostic and check the codes to see if they are related to the bad fuel pump or not.
Generally, a bad fuel pump won’t set a code. It’s wiring issues that do. There might be something wrong with the computer such as a bad backlight or even something that’s related to the fuel pump’s internal wiring.
How can you test if your fuel pump is bad?
If your check engine light comes on, a code reader can help you determine if the issue is a bad fuel pump or something else. You’ll need to bring your vehicle to a repair shop for them to run a diagnostic test, as not all lights are related to fuel pumps.
It’s best to run the tests when the check engine light is on because that’s when the issue is happening. Sometimes, it’s just a false alarm and you can check for codes again later when the check engine light turns off automatically.
Tips to Maintain Fuel Pumps in Good Condition
Here are some tips for maintaining a car’s fuel pump and helping it last longer:
- Keep your gas tank at least a quarter full: Running on a low fuel level can cause the fuel pump to work harder and potentially overheat. Keeping your tank at least a quarter full can help reduce the workload on the fuel pump.
- Change your fuel filter regularly: A dirty or clogged fuel filter can cause the fuel pump to work harder and reduce its lifespan. It is recommended to change the fuel filter every 30,000 miles or as recommended by the manufacturer.
- Use quality fuel: Using low-quality or contaminated fuel can cause damage to the fuel pump and other components of the fuel system. Use high-quality fuel from reputable sources.
- Drive gently: Driving aggressively, accelerating quickly, and sudden stops can cause the fuel pump to work harder and potentially fail prematurely. Drive gently and avoid harsh driving habits.
- Keep up with regular maintenance: Regular maintenance, including oil changes, tune-ups, and inspections, can help identify and prevent potential issues with the fuel pump and other components of the vehicle.
By following these tips, you can help maintain your car’s fuel pump and increase its lifespan.
Frequent Asked Questions
What are the symptoms of a bad fuel pump?
There are a few common symptoms that may indicate a bad fuel pump. These include:
- Engine sputtering or stalling: A failing fuel pump may not be able to provide the engine with enough fuel, causing it to sputter or even stall out.
- Difficulty starting: If your vehicle is having trouble starting, it may be due to a weak fuel pump that is not able to pump enough fuel into the engine.
- Decreased fuel efficiency: A bad fuel pump can also lead to decreased fuel efficiency, as the engine may not be getting the proper amount of fuel it needs to run efficiently.
- Engine surging: In some cases, a failing fuel pump may cause the engine to surge or hesitate while driving, which can be dangerous.
What are the consequences of driving with a bad fuel pump?
Driving with a bad fuel pump can be dangerous and can cause damage to other parts of your vehicle. Some potential consequences of driving with a bad fuel pump include:
- Stalling: If your fuel pump completely fails while driving, your vehicle may stall out, which can be dangerous if you are on a busy road or highway.
- Engine damage: A fuel pump that is not working properly can cause damage to your engine over time, as it may not be getting enough fuel to run efficiently.
- Expensive repairs: If you continue to drive with a bad fuel pump, it can cause damage to other parts of your vehicle, such as the fuel injectors or fuel filter, which can be expensive to repair or replace.
How do I know if I have a bad fuel pump?
There are a few signs that may indicate you have a bad fuel pump. Some of the most common symptoms include:
- Engine sputtering or stalling
- Difficulty starting
- Decreased fuel efficiency
- Engine surging or hesitation
- Check the engine light on
- Loud whining noise is coming from the fuel tank (this may indicate the fuel pump is working harder than it should be)
If you are experiencing any of these symptoms, it is best to have your vehicle inspected by a mechanic to determine the cause.
How to check if a fuel pump is bad?
There are a few ways to check if your fuel pump is bad, including:
- Use a fuel pressure gauge to check the pressure of the fuel system
- Listen for a whining noise coming from the fuel tank (this may indicate a failing fuel pump)
- Check the fuel pump fuse and relay to ensure they are working properly
- Have a mechanic inspect your fuel system to determine the cause of any symptoms you may be experiencing.
It is important to have your fuel system inspected by a professional if you suspect your fuel pump is not working properly, as attempting to repair or replace it yourself can be dangerous and may cause further damage to your vehicle.
What are some common causes of a bad fuel pump?
There are several factors that can contribute to a bad fuel pump, including:
- Age and wear: Fuel pumps can wear out over time, especially if they are not properly maintained or replaced when necessary.
- Contaminated fuel: Dirt, debris, or other contaminants in the fuel can clog the fuel pump or cause it to fail.
- Overheating: If the fuel pump overheats, it can cause damage to the motor or electrical components, leading to failure.
- Electrical problems: Issues with the wiring, relays, or other electrical components in the fuel system can cause the fuel pump to malfunction.
How do I replace a bad fuel pump?
Replacing a bad fuel pump can be a complex and potentially dangerous process. It is recommended that you have a professional mechanic perform the replacement to ensure it is done correctly and safely.
However, if you are experienced with automotive repair and have the proper tools and equipment, you may be able to replace the fuel pump yourself. The process generally involves draining the fuel tank, disconnecting the fuel lines and electrical connections, removing the old fuel pump, and installing the new one.
Any engine code for bad fuel pump?
There are a few engine codes that may indicate a bad fuel pump, including:
- P0230: Fuel Pump Primary Circuit Malfunction
- P0231: Fuel Pump Secondary Circuit Low
- P0232: Fuel Pump Secondary Circuit High
- P0463: Fuel Level Sensor Circuit High Input
If you are experiencing any of these codes, it is recommended that you have your vehicle inspected by a professional mechanic to determine the cause and necessary repairs.
How do I prevent a bad fuel pump?
There are several steps you can take to help prevent a bad fuel pump, including:
- Regular maintenance: Regularly scheduled maintenance, such as fuel filter replacements, can help prevent debris from clogging the fuel pump.
- Use high-quality fuel: Using high-quality fuel and avoiding contaminated fuel can help prevent damage to the fuel pump and other components in the fuel system.
- Avoid overheating: Avoid driving in extreme heat or towing heavy loads for extended periods of time, as this can cause the fuel pump to overheat.
- Address electrical issues promptly: If you experience any issues with the electrical components in the fuel system, such as a blown fuse or relay, have them addressed promptly to prevent damage to the fuel pump.
How does a car act when the fuel pump is going out?
When a fuel pump is going out, it can cause a variety of symptoms, such as:
- Engine sputtering: A failing fuel pump may not be able to deliver enough fuel to the engine, causing it to sputter or stall.
- Loss of power: If the fuel pump is not delivering enough fuel to the engine, it can cause a loss of power or acceleration.
- Difficulty starting: A failing fuel pump may make it difficult to start the engine, or it may take longer than usual to start.
- Engine misfires: If the fuel pump is not delivering a consistent flow of fuel to the engine, it can cause misfires or a rough idle.
- Strange noises: A failing fuel pump may make unusual noises, such as whining or buzzing, as it struggles to deliver fuel.
It is important to address these symptoms promptly, as a failing fuel pump can cause further damage to the engine if left unrepaired.
Will a bad fuel sending unit cause a check engine light to come on?
A bad fuel sending unit is responsible for sending the fuel level information to the vehicle’s fuel gauge. While a malfunctioning fuel sending unit can cause issues with the accuracy of the fuel gauge, it typically would not cause a check engine light to come on.
However, if the fuel sending unit is causing issues with the fuel pump or other components in the fuel system, it could potentially trigger a check engine light. If you are experiencing issues with your fuel gauge or check engine light, it is recommended that you have your vehicle inspected by a professional mechanic to determine the cause of the issue.
A bad fuel pump can cause the check engine light, but it’s not always the issue. You should always have a mechanic take a look at it because there are other issues that could be causing your problems.
Since having a bad fuel pump is not an uncommon problem, you might get lucky and not need to replace it. It makes sense to get the car towed to a repair shop and have them fix it for you.
- 14 CFR § 25.991 – Fuel pumps
- 33 CFR 183.524 – Fuel pumps. – Content Details
- How to Check Your Fuel Pump: 7 Steps
- How to Start a Car with a Bad Fuel Pump
Hi, My name is Ollie Barker.
With 25 years working in repair and detailing shops. I’d love to share my tips & tricks to all car lovers. Also, give my recommendations on which products are the best to have on the market.
Thanks for visiting CarDetailingArt! Hope you enjoy your time on my little blog!