How do I turn off the check engine light? Here are the 2 ways


Why is the engine misfire light on?

The misfire warning light is one of the most general of all car warning lights. There are many anomalies or problems in the car that cause it to come on. Before understanding how to turn off the engine misfire warning light, it is better to have a good idea first why the engine misfire light has come on.

Let's see what are the main causes of engine misfire light failure:


  • Exhaust system failure.
  • Clogged or faulty EGR valve
  • Fuel system problems
  • Catalytic converter failure
  • Accelerator pedal sensor faults

What does the misfire light indicate?

Before explaining how to turn off the misfire light, it is helpful to understand what the misfire light indicates. Remember that the engine misfire warning light can be either steady or flashing.

In the event that the misfire light is flashing, the car probably has a problem with the catalytic converter (also called a catalytic converter) sending incorrect readings to the control unit. Although this is not a critical problem for the car if the ECU continues to work with incorrect data, various engine components will suffer from excessive wear or operate sub-optimally.

If the engine misfire warning light is permanently on, then there is a problem with the fuel system. There may also be incorrect fuel in the fuel tank. In this case it is advisable to stop, switch off the engine and wait a few minutes before restarting the car and checking that the warning light goes out.

How does the engine failure light go out?

If there is no reason or anomaly that could cause the engine warning light to come on, then there is likely to be an electronic malfunction or ECU error. There are two techniques that can be used to turn off and reset the engine misfire warning light.


Let's look at how to turn off the engine misfire warning light:

  • The engine misfire warning light can be reset using acar diagnostic tool.
  • We can turn off the engine misfire warning light with the so called "kitchen method"...

Both of the techniques for turning off the misfire light just mentioned and soon to be described should only be performed by those who have a minimum of manual car skills. If your knowledge of cars is nil, we suggest you save your time and rely on a mechanic who can do a better job.

How do I turn off the check engine light with the diagnostic tool?

The diagnostic tool we are referring to is the "OBD-II scanner" where OBD stands for On-Board Diagnostics, on-board diagnostics for those less English than us. These types of tools are useful for collecting and analyzing data on almost all vehicles produced after 1996. These scanners are quite expensive and so we advise you to borrow one from a friend or a local garage or electrician.

Once we have obtained the OBD-II scanner to turn off the misfire light we must connect it to the appropriate connector located under the column or pillar of the car. To protect it from dust, this connector is usually covered by a plastic cover that we will have to remove for the duration of this procedure.

Once the OBD-II scanner is connected to the appropriate connector we will have to insert the car key turning it to the ignition without starting the engine. We turn off all electrical equipment such as the radio or air conditioning. After that we will have to press the scanner read button. We should see a series of codes which, depending on the scanner model, may also have an explanation attached to them. Each of these codes indicates an anomaly in the car and you should take note of them in order to solve it.


On the list of codes should be one related to the engine warning light, sometimes identified as "check engine alarm". If you're still wondering how to turn off the check engine light, it's very simple. Just select the code and click the Clear or Reset or Reset button. The next time you start the car you should not have the misfire light on.

How do I turn off the misfire light using the horn technique?

If you're a fan of the old ways or just don't have an OBD-II scanner with you, you can turn off the check engine light using the horn technique.

To turn the car off using the horn technique when the car is off, you have to disconnect both battery terminals to remove power to the control unit. Once this is done, get into the car and keep the horn pressed for at least 30 seconds. Now wait about 15 minutes.

This way, you are discharging all the remaining electrical energy in the capacitor and you will reset the control unit. This technique is a bit like switching on and off, useful for resetting many appliances.


After 15 minutes you can reconnect the battery cables and restart the car. If the engine fault light is off, then it was just an electrical fault. If the light comes back on, it means there is a problem with the car and you should take it to a mechanic who will show you how to fix the problem permanently.

When shouldn't we turn off the misfire light?

If the misfire warning light is accompanied by other lights it may be necessary to further investigate the cause of the ignition. This is because there may be a serious engine problem.

It is always helpful to know how to turn off the engine misfire warning light, however, you should not attempt a reset if the coolant temperature warning light is also on. The combination of these two lamps can indicate a leak in the cooling system and/or damage to the engine head gasket.

Therefore, our advice is never to reset or turn off the engine misfire warning light in the presence of other lights on the car.

What to do if the engine warning light stays on?

Have you learned how to turn off the check engine light, done it several times and the light always comes on again after a short time? Chances are that the warning light comes on again because there is a problem causing it to come on, nothing more complicated than that.

In this case, it is imperative to take the car to a mechanic and ask for help to turn off the misfire light and solve the problems causing the ignition to come on. In the meantime, we advise you to take a look at the article where we explain what to do if the misfire engine light is on.



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