Check Engine Light Flashing When Accelerating (Causes & Fixes)

We all know the feeling of getting into your vehicle and noticing the check engine light is on. This is something that we all dread and is made even worse when it seems to only happen when accelerating. Luckily, I have compiled a guide detailing all of the major causes of these issues for you.

A check engine light that flashes while accelerating is a sign that there is a problem with the engine block. The most probable culprits are the crankshaft position sensor, the fuel delivery system, or the air intake system of the vehicle. To solve the problem, the first thing that your should do is to scan the vehicle with an OBDII diagnostic tool, then clean or replace the component that is causing the problem.

The rest of this guide will provide more details on these issues so that you can identify and resolve them more easily. The important thing is to stay calm when dealing with check engine light issues, as only a few causes are serious.

What Is The Check Engine Light ( And What Does It Do)

As part of the car’s computer system, the check engine light comes on when the engine is running low on fuel.

There are a number of sensors throughout the vehicle that are used to monitor engine performance, fuel mixture, and emissions. When a problem is detected by the system, the light will come on.

In modern cars, there are a variety of sensors that monitor various aspects of the car. One of the most common sensors in engines is the oxygen sensor, the mass airflow sensor, the throttle position sensor, and the temperature sensor for the engine coolant.

It is common for the check engine light to illuminate when one of these sensors malfunctions. It is possible that the issue might be with the computer of the car itself in some cases.

If you begin to notice your check engine light coming on, then it is very likely there is an issue with your car, so you should take note of it. In most cases, this is something that should be addressed and should not be ignored. Luckily, there is no need to panic either.

Now that we have the basics of the check engine light covered, you may be interested in how much the average cost to repair a flashing engine light is. This will be covered in the next section.

Average Cost To Repair A Flashing Engine Light

It can be difficult to estimate the actual cost of fixing a flashing check engine light will be, since it is dependent on the reason for the problem, so the estimated cost range can be between $50 up to $1000.

In most cases, if the problem persists, it can be resolved easily by changing some service items, such as spark plugs or engine filters, in which case it can be a cheap fix. In most cases, this will cost between $50 and $100, and you may have to hire a mechanic to take care of the job if it’s beyond your abilities.

It is possible for the problem to become more expensive if the engine sensor of the engine or the ignition coil is faulty.

It can cost anywhere from $40 to a few hundred dollars to repair a sensor on an engine like a mass air flow sensor or a camshaft position sensor for a variety of engines.

The cost of replacing an ignition coil is usually more expensive, with the cost of an ignition coil repair running well into the hundreds of dollars, or even exceeding $1000 on newer, higher-end vehicles.

Depending on the severity of the problems (whether the component needs to be replaced) and the actual amount of labor that is involved, a turbocharger repair, EGR valve repair, fuel injector repair, or fuel pump repair may cost anywhere between $150 and $800.

Being able to properly identify the cause of your check engine light flashing will help you better determine your total costs of repair. We will cover the most common causes of a flashing check engine light in the sections below.

Reasons For A Flashing Check Engine Light

The sections below will detail many of the most common causes of a flashing check engine light. Understanding the different causes of this issue will help you navigate the troubleshooting process and hopefully lower your stress about the situation in general.

Faulty Engine Control Unit

In order to monitor the fuel intake in a car, the Engine Control Unit is an integral part. An ECU will receive a signal when there is a malfunctioning of any of the components of the fuel system.

If the ECU has some issues, it will not be able to control or monitor the fuel systems, such as the fuel injectors. This will result in the check engine light starts to flash, as the ECU cannot control or monitor the fuel systems.

If you are still having issues, the fuel delivery system of your vehicle could be causing your problems. Inspecting this element of your vehicle could help you solve your problem.

Fuel Delivery System Problem

An issue with the fuel delivery system can be one of the causes of a flashing check engine light or even a reason your car will shake. It is not uncommon for a fuel filter to become dirty, injectors to clog up, or a fuel pump to malfunction to cause this problem.

There are a number of components in the fuel delivery system that works in tandem to deliver fuel to the engine as efficiently as possible. There is also the possibility that your check engine light will illuminate on as a result of any of these components not working appropriately.

As the engine accelerates, more fuel is required by the engine to keep up with the acceleration. It is also common for the check engine light to illuminate if the fuel delivery system is unable to meet the demand for fuel.

Another common component that causes the check engine light to flash is a faulty oxygen sensor. This component of your vehicle is relatively easy to inspect and can give you some peace of mind while moving through the inspection process.

Faulty Oxygen Sensor

The oxygen sensor plays a vital role in the proper operation of your car; without it, the engine of your car will not be able to run properly. A sensor of this type regulates both how much oxygen is needed to burn the fuel and how much unburnt fuel is being exhausted.

It is important to realize, however, that a bad oxygen sensor does not mean you cannot drive your car. The only problem is that the catalytic converter will be exposed to gradual damage, and you will be able to get lower MPGs as a result.

There is a possibility that the broken oxygen sensor in your vehicle may not work properly when you accelerate your vehicle. This may cause some of the engine parts to be damaged, and a check engine light will begin flashing when you accelerate.

If you still haven’t been able to find the cause of your problem, it’s time to move on to other components like your spark plugs. These are relatively easy to inspect.

Bad Spark Plugs

An important part of your car is the spark plugs, as they provide a continuous supply of sparks to keep the engine running at its best. Consequently, if the spark plug develops a fault such as wear and tear or a malfunction, it will not provide enough sparks to the engine.

When you accelerate a car, for instance, the engine will need more sparks in order to burn the fuel in the combustion chamber of the engine as it is accelerating.

 It is likely that if the spark plug in the engine is broken, there will be a delay in the combustion effect, and this will result in the misfiring of the motor and even knocking off the engine if the spark plug is damaged. A check engine light will be displayed on the dashboard in this case, and you will be able to see it flashing.

After you have inspected your spark plugs, you should take into account the temperature of your motor while accelerating. Engine overheating is a common cause of a lit-up check engine light and can indicate a serious problem. Don’t worry, we will cover this in the section below.

Engine Overheating

The problem of engine overheating is a serious one that cannot be ignored. There are several reasons why an engine can overheat, for example, if either the cooling system or the engine’s operating system has failed, then the engine will overheat.

A coolant can be any of a number of fluids, such as oil, air, water, or a mixture of the three. In the event that there are not enough or inadequate cooling systems in the engine, the engine will overheat as a result of friction between some engine components and combustion activities.

Additionally, pool engine cooling systems can also be dangerous, especially if you accelerate your car to a high speed.

Engine Overheating

There is the possibility that this could be one of the results of checking if the engine light flashes when you increase the speed of your car.

Whenever your car’s computer detects that the engine is overheating, it will send you a warning signal on the dashboard to inform you that there is a serious problem taking place with the engine.

A less serious issue that could be causing your check engine light to light up is camshaft sensor problems. If we haven’t yet reached the cause of your issue, this is the next component to inspect for problems.

Camshaft Sensor Problems

In the car, the camshaft position sensor is in charge of monitoring the speed of the engine as well as the position of the camshaft. In turn, the ECU is responsible for sending such information to the car’s engine control unit in order for the ECU to regulate the amount of fuel needed to enter the combustion chamber, as well as the timing of the spark to ensure that fuel is ignited.

The fuel intake and ignition timing of your car should be adjusted at high levels when you accelerate your car. A bad camshaft sensor, thereby, would suggest a poor rationing of fuel intake and spark timing, which would indicate a problem with the engine as a whole.

If there is a problem with the camshaft sensor, most of the check engine lights will light up when the driver presses the gas pedal. This particular case can be caused by a damaged or worn throttle position sensor, which is the most likely cause of such a situation.

Finally, the last issue we will discuss that commonly causes check engine lights to light up is the charging system misfires. I know this sounds like a serious problem but it is not as bad as it sounds. We will cover this issue next.

Issues With The Charging System Misfire

There must be a specific operation order for the fuel, oxygen, and ignition timing in your car’s engine in order to operate properly even when you accelerate, and that order has to be followed by the engine.

There is, however, a possibility that when there is a malfunctioning of one or more of the cylinders, the engine system might experience some issues and then the check engine light will start flashing, indicating that something needs to be repaired.

Some circumstances, however, may result in an intermittent flashing of the check engine light that will illuminate for a very short period of time, or the flashing may exist as a continuous illumination of the check engine light.

It is important that you keep in mind that such situations are not very serious, and you can continue driving before reaching your mechanic.

Now that we have walked you through most of the common causes of a lit-up check engine light while accelerating, we can discuss what you should do next to resolve the issues.

What To Do When Your Engine Light Starts Flashing?

As we’ve covered some of the possible causes of a flashing check engine light, let’s take a look at some of the possible solutions to the problem.

Using a diagnostic tool is the best first measure you should take if you are experiencing an error in the system, as it will help you identify the true cause of the error. In this way, you will be able to take the necessary steps in order to resolve the issue.

If you have figured out exactly why the check engine light has come on, then you can take the appropriate steps to address the problem as soon as you do so. It might be as simple as replacing a dirty air filter in some cases, but in others, it could be a different issue altogether.

As a result, it could be necessary to perform more extensive repairs, such as replacing an engine sensor or an ignition component, in other cases.

It is always better to have your vehicle serviced by a certified mechanic if you don’t feel comfortable working on it yourself. The technician will be able to diagnose the problem and make the necessary repairs as soon as possible.

Is It Bad To Drive With A Flashing Engine Light?

If the check engine light starts flashing on your dashboard, it is not advisable for you to drive your car.

This is important because, if you don’t take action, your engine may suffer further damage, resulting in more expensive repairs if you don’t correct the problem. The best thing for you to do if you have to drive is to take it easy on the accelerator and avoid driving at high speeds.

Now that we have covered most of the basics of check engine lights while accelerating, it will be helpful to know some of the more common engine light codes. This will save you some time when trying to identify the error codes thrown by your ECU.

Most Common Flashing Engine Light Codes

In the event that the ECU detects an issue with the engine, the check engine light will light up on the dashboard. An error code is assigned to each error cached in the ECU in the form of a “P” code.

It is the best way to determine the cause of a check engine light illuminated by connecting a diagnostic reader to your vehicle and reading the stored codes that will tell you what is wrong. As soon as you have the code(s), it will be much easier for you to identify the faulty component once you have the code(s).

Listed below are some of the most common P codes associated with the check engine light that you may encounter:

  • P0300- Random misfire detected code
  • P0302- Cylinder misfire detected
  • P0420- Catalyst system efficiency below threshold
  • P0455- EVAP system large leak detected
  • P2463- Diesel particulate filter restriction – Soot accumulation

Final Thoughts

If you begin to notice that your check engine light is flashing while you’re driving, it could be a strong indication that you have a problem with your engine sensor, a vacuum leak, problems with your fuel delivery or ignition system, or even a major mechanical problem that could cause your engine to misfire.

To determine the actual cause of the issue, you use a diagnostic tool, such as an OBDII. Based on the error code, you can determine the appropriate course of action.