How To Reset Check Engine Light


Initially, this light gave you information about problems with the carburetor, but now that cars are equipped with full-fledged onboard computers, the message can indicate various malfunctions.

For example, the “check engine” error can report problems with the quality of the air-fuel mixture or ignition failures, as well as many other things.

Messages can be caused by both minor breakdowns and critical ones.

Thus, when the “Check Engine” is lit, it is only clear that the ECU has detected a fault in one of the car’s systems.

Only diagnostics can give a complete picture. Next, let’s look at the main reasons why the “Check Engine” light is lit, and what to do with it.

Reasons why the “Check Engine” light is on

1. The fuel tank cover is open. Make sure it’s closed tight.

2. Bad gas. The system can respond to fuel quality. The solution will be to drain the gasoline and pour a better quality.

3. Oil level. First of all, check its level with a dipstick. Also, check for cracks in the block and oil leaks.

4. Problems with the gas pump or the mesh in the tank. Make sure that the pump is running smoothly and that it doesn’t make any strange sounds.

5. Contaminated force-pump. Solved by cleaning the force-pump

6. Failure of high-voltage wires or coils.

7. Problem with the spark plugs. The icon also lights up when there are problems with candles. It is worth checking the performance of the candles and replacing them if necessary.

8. No spark in one of the cylinders.

9. The oxygen sensor is faulty. The problem is resolved only by replacing this part.

Only the main reasons and solutions are listed here. In fact, there are many more. Diagnostics of the on-Board computer, which monitors all the systems of the car, can give a more complete picture of the situation.

Diagnosing the “Check Engine” light 

Let’s take a closer look at the steps that you need to take in the first place in order to get rid of the Check Engine indicator that is lit up.

1. Check if the gas tank cover is closed. This situation is especially relevant if you have just left the gas station, and soon after the “check engine” icon lights up. This means that either the leak-tightness of the fuel system has been broken due to an insufficiently tight tank cover, or the quality of the fuel leaves much to be desired

2. Check the condition of spark plugs. To do this, Unscrew them and visually assess their condition. Very often, spark plugs are the reason for activating the Check Engine indicator. In particular, the reason may be that they begin to pass current due to the deposition of carbon on the electrodes. This plaque is formed as a result of the high content of metals or other conductive substances in the fuel. An error may also occur if the gap between the electrodes on the candle exceeds the distance of 1.3 mm.

3. Oil level. If the check engine icon lights up only when the engine is hot, stop and listen, you may hear extraneous sounds in the engine. Use a dipstick to check the engine oil level and top it up if necessary. Also, check for any oil leaks.

4. If your car is equipped with sensors that check the purity of fluids (engine oil, fuel, and so on), the indicator may light up if the corresponding indicators exceed the permissible limit. The solution is to replace the appropriate filters or completely replace them if they do not meet the standards.

5. Reset the negative terminal from the battery (15…20 seconds). After that, the Check Engine lamp should go out, and the clock on the computer should reset to zero. This method may be relevant in two cases. The first is a being a “glitch” of the ECU. The second is if the memory of the electronic unit has accumulated a large number of small errors that were not reset. (usually, they are caused by the use of low-quality gasoline, the presence of harmful impurities in the fuel-air mixture, moisture on the electrical contacts, and so on).

How to reset the check engine light

Methods below will work for almost any car such as Toyota, Dodge, GMC, Chevy, Honda etc.

Using a OBD2 scanner

1. Using a diagnostic tool is the easiest way to reset the engine check indicator. Here are 5 simple steps

2. Connect the scanning tool to the on-Board diagnostic connector under the steering wheel. You will need a phone or a computer with the necessary software

Image of connecting The Scanner under The steering wheel
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3. Then turn on the car’s ignition and turn on all the gadgets

4. On your mobile device (or on the scanner itself, depending on your scanner type), in the corresponding section, click “READ” to view the engine error codes. Using a pen, write the code in the order in which they were received. This will be necessary for subsequent repairs.

5. Click the “ERASE” button on the scanner. The “Check Engine” indicator will turn off if all error codes are cleared. Some scanning tools have many options, such as a freeze-frame that captures the sensor readings. When deleting codes, these readings are also deleted.

Note: in some scanners, the code clearing option may be automatic and the “CLEAR” or “YES” button instead of the “ERASE” button.

6. Don’t forget to turn on the ignition before deleting the codes.

Battery Disconnection Technique

Car battery under the hood.

Disconnecting the battery is an old way to reset the engine indicator check. Here are three steps to reset the “check” using this method:

1. Disconnect the cables from the battery. At this stage, you should use a wrench to Unscrew the positive and negative cables.

2. The next thing you have to do is press and hold the car horn for about 30 seconds. This action will help to discharge the car’s battery.

3. After disconnecting the battery cables and draining the remaining electricity, all you have to do is wait for about 15 minutes and then plug the battery back in. Error codes will be deleted.

(Note: this method may not work on some vehicles). If the “check” lights up again after this procedure, it may mean that the problem is still much more serious.

If you want diagnose your car battery you can check out our article on it

Turning the Ignition On and Off

Ignition switch

Similar to the second method, but without disconnecting the battery.

You just need to turn the car’s ignition on and off three times in a row with an interval of a second at each step.

After you are done, start the car and check whether the indicator is reset or not.

Let the “Check Engine” indicator go out itself

This is the easiest method because you almost don’t need to do anything.

The computer system in most cars will automatically recheck problems that may activate the error indicator.

If this is a minor problem, it will automatically correct itself and the “Check Engine” will go out.

However, if “Check Engine” is still lit for three days, you need to apply the methods mentioned above to reset it.

If this continues to happen despite the following reset procedures, you should show your car to the nearest service station and have it diagnosed by a professional mechanic.

Professional diagnostics use more sophisticated tools and allows you to identify exact problems.

If The “Check Engine” light returns

If you’ve checked all of the methods listed above and the “check engine” light disappeared but then reappeared after a few days again, then that indicates a huge problem with your car.

If you used a scanner and you don’t see the same problem code again, it means that a new fault has occurred in your car.

But if the same code still remains on the scanner, then in this situation it is strongly recommended that you go and have an appointment with a qualified mechanic/technician to get a full diagnosis on your car with a decent OBD2 scanner.

How to get to the service station with the “Check Engine” light on

When driving to the service station , try to maintain a gentle ride.

1. Do not exceed the speed limit of 60 km / h

2. Do not exceed the engine speed of more than 2500 rpm

3. Turn off the air conditioner, multimedia system, and other currently unnecessary equipment that creates additional load on the engine

4. Avoid sudden starts and deceleration, drive smoothly.


If the Check Engine indicator lights up, don’t panic.

In most cases, the reasons for its activation are not critical.

However, it is necessary to perform a diagnosis consisting of steps listed above. Also, check whether the car’s behaviour on the road has changed and whether other indicators have also lit up.

If minor errors are detected, you need to correct them.

If the Check Engine does not go out after that, then perform additional diagnostics using an electronic device.

It will give you an error code indicating the cause of the failure.

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