Check Engine Light Went Off After A Week (Explained!)

Feeling intrigued by your check engine light going off after a week? Are you wondering what this means and whether you should still have your car diagnosed? If you’re looking for an answer to all these questions, you’ve come to the right place.

If the check engine light went off after a week, it means the problem has resolved itself. Your car diagnostic system is continuously running tests and when your car passes a test it has failed earlier; the light will go off on its own.

This guide sheds more light on your check engine light coming on and then going off after a week. We’ll give you all the possible reasons why this happens and what to do to ensure your car doesn’t develop any issues afterward.

Why your check engine light went off after a week

Most car owners have experienced this before—the cheek engine light comes on and hangs around for up to a week and then, one day, while you’re driving, it disappears on its own.

You didn’t take your car to the mechanic to have the problem fixed, so you can get quite curious about how the light decided to clear off on its own.

The explanation for this is that the problem that caused the CEL to come on may have been corrected, so the light has no business alerting you of an error that needs to be checked and will simply turn itself off.

Your car computer is continually running some tests when you’re driving your car. These include tests like engine timing, misfires, air-fuel ratio, EVAP system, and more. If the car fails up to two tests subsequently, then CEL is triggered to let you know the engine has a problem that needs to be checked.

Let’s assume you ignore the light and don’t do anything about it. In this case, your car computer will not stop running the tests.

It carries on and if the engine passes the tests it has failed earlier on, then the check engine will go off. This can take a week(s), days, or even hours depending on the type of issue your engine has.

In a rare occurrences, you should also check whether the check engine light bulb may have burned out, causing it to go off on its own. The best way to check whether the light is working correctly is to see how it behaves when you put the key in the On position.

If it doesn’t come on, it means the bulb is blown and you should replace it with a new one as soon as possible.

Should I still have my car checked after the light goes out on its own?

Absolutely! Unlike what many car owners tend to convince themselves, the check engine light clearing off on its own doesn’t necessarily mean the underlying problem has been solved.

After all, the check engine light going off basically suggests the car is fine.

As we have explained above, it simply means your car run some internally controlled tests and the car passed the test it failed earlier, thus putting off the light.

We still advise you to visit your mechanic so they can diagnose your car fault codes using a code reader and find what caused the light to appear in the first place. Only then can you understand why the light turned itself.

You may find out that although the light went off after passing the test, the engine could still be experiencing a more critical mechanic issue somewhere. Taking your car to a mechanic is a good bet to avoid incurring high repair costs in the future.

In some cases, the warning light may have come on due to the electronic control unit (ECU) reading the signals wrong or it may have some issues itself that need to be checked. This is especially true if the CEL keeps alternating between on and off.

Remember, an issue caused the CEL to come on in the first place and the best way to get to the bottom of it is to have your car diagnosed by a mechanic.

Why would your check engine light come on for a few days and then go off?

Sometimes the light will hang around for a few days, say 2-3 days, instead of a week and then go off. In this case, the problem may also have been resolved.

As we said earlier, your car computer keeps running tests when you’re driving your car. If it no longer detects the problem that caused it to activate the CEL, it will just deactivate it.

You may find out the issue may have been as minor as a loose gas cap that wasn’t properly screwed or the engine got wet and caused a misfire.

The best way to find out why your warning light does this is to scan for the trouble codes using an OBD2 scanner. Your local auto parts store can also pull the codes for you for free.

This way, you’ll have an idea of what’s wrong with your car and whether you need to get a mechanic to work on it.

If you don’t have a scanner, you can try using the elimination method depending on your driving habits and conditions. Paying attention to coolant temperature and fluid levels can help in isolating the issue.

What if the check engine light comes on for days, goes off for a week, and then turns on again?

If the CEL stays on for a few days, goes off for a week, only to come on again, then you’re dealing with an intermittent problem. This is detected by your car computer which then alerts you by triggering the check engine light.

Now, when you stop driving your car, the fault will get logged into the computer memory if it’s critical and the light will stay on again when you start your car.

If the issue was minor, however, it won’t get marked. The next time you’ll be driving your car the fault would have reset and the CEL won’t come on.

A perfect example of an issue that causes intermittent fault is a failing engine sensor. It keeps doing so until it fails completely and can be challenging to detect/diagnose. A misfire from a coil that’s occasionally breaking down is another example of an intermittent problem.

The best way to go around this issue is to use a scanner to pull up the code history. This will help you find out what issue your car engine is experiencing and repair it before it becomes a more serious issue.

Keep in mind that the light may keep going on and off and finally stay on continually and finally go away until you fix the problem. So, it’s best to solve the issue as early as possible.

Should you continue driving your car after the check engine light goes off by itself?

You can continue driving your car after the check engine light goes off by itself after days or a week.

After all, you have been driving the car for all those days with the warning light on and nothing has happened, so you shouldn’t stop when it goes off.

The CEL going off is a sign that your car is fine and has no engine issues or the underlying issue has been fixed and everything is fine now.

The only time you should rethink driving your car is when the opposite happens—i.e., the check engine light comes on blinking. This is an indicator of a critical issue that needs immediate action.

In this case, we advise you to pull over as soon as it is safe to do so and get a mechanic to diagnose your car and repair the problem before it grows into a more serious problem.

However, we still strongly recommend that you have your car checked by a mechanic to find out what made the light come on.

A reputable mechanic will scan your car for the trouble codes to give them a clue about what has been ailing your car and advice you accordingly.

Do error codes stay in the vehicle computer after the light goes off by itself?

Yes! The diagnostic trouble codes that caused the CEL to come on are usually stored in the car computer whether the light has resolved on its own or you have fixed it. The codes usually clear after you drive your car for a given number of miles.

This means if you take your car to a mechanic after the light goes off on its own, they can still query the codes your car has stored and find out what caused the light to come on.

if you want, you can also diagnose your car for the fault codes on your own and find out the cause of the CEL to come on.

You just need to hook an OBD II scanner into a socket located under your dash. You get the codes and then look them up to find out what problem they mean.

Google has a list of common trouble codes chart freely available at the press of the search button, so finding what a fault code means shouldn’t be a problem for you.

These scanners are pretty affordable and readily viable, so getting a unit for yourself shouldn’t be a problem.

Note that you can also use this device to delete the trouble codes from your vehicle’s memory using the ERASE function.

If you’ve been dealing with a check engine light that went off after a week, you may be wondering what could have caused it. Our article on check engine light disappeared covers some common reasons why the light may have turned off on its own and what you can do to prevent it from happening again. On the other hand, if your check engine light keeps coming on and off, it’s important to diagnose the issue properly. Our article on check engine light comes on and off discusses some possible causes and solutions for this issue, so you can take the appropriate action and ensure that your vehicle is running smoothly.

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Final Verdict

The check engine light usually comes on to alert you that your engine has a problem that needs to be fixed, and only goes off when you fix the issue. As we have seen in this guide, however, the CEL may go off after a week on its own without a mechanic’s intervention. This usually suggests that the problem causing the light to come on has resolved on its own.

While you may feel lucky about the light going off on its own, we still encourage you to have your mechanic check your car to find out what caused the warning light to come on in the first place. This is a good precaution since you may find out that your engine has a bigger mechanical issue that may cost you dearly on repairs in the future. So, make you’re your car gets checked to ensure it’s fine, even if the light went off after a week on its own!