Last Updated on 11 months by Ollie Barker
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.
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 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.
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.