How to Reset Check Engine Light (4 Methods with Guide)

Jerry Wilson
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Why You Might Need to Reset Check Engine Light

The emergency light of your car is called Check Engine Light and it is generally referred to as a check-engine or engine check light (in some countries the light might be called a check-engine-soon (CEL) or malfunction indicator light (MIL)). Its main function is to signal the driver that there is a problem with the car’s engine management system.

The problem can be severe enough not to drive the car without the mechanic’s permission or light can signal something minor like a loose gas cap, dirty sensor, or loose connections. It can even signal that the light itself no longer works properly.

Whatever the reason, when the light turns on, it is usually the only indicator that something is wrong and you need to take your car to the mechanic.

How to Reset Check Engine Light

(Trouble Code Reader)

The check engine light doesn’t always mean something’s wrong. In fact, your car may be running fine. The check engine light is supposed to help technicians diagnose problems, so it typically won’t go on unless your car’s emissions equipment or an onboard sensor is faulty.

However, it’s important to take a trip to your mechanic if your check engine light is on. You have to have the problem diagnosed and fixed by a professional because it’s illegal to tamper with your vehicle’s emissions control system.

The common first step is to connect your car to a computer, either with a laptop or a mobile device. This process is called "trouble code reading." Your mechanic will then search your car’s memory for an error code or diagnostic trouble code.

These codes help mechanics find what’s wrong with your car. There are over 2,100 OBD-II trouble codes in existence. These codes range from 1 to 5 and everything in between. The codes give mechanics and technicians insight into what’s going wrong with your car.

Method 1: Check and Fix the Problem

If the check engine light is on, you should be able to pull up a code by paying a visit to an auto parts store or a professional mechanic.

Or you can use code reader such as Actron CP7880 AutoScanner by following the instructions that come with it.

Once you have the code, you can either research it online or take your car to the mechanic and ask him or her to identify the problem.

The issue is likely a common one, such as leaning to one side or running too hot. There are a number of things you can do on your own, including checking fluids, replacing things like spark plugs and air filters, and resetting anything that may have changed settings.

Services such as AAA and motor clubs also offer auto repair discounts to members.

Method 2: Use OBD-II Scanner

Please follow steps below:

{1}. Find a size-appropriate OBD-II scanner (free or paid) to check diagnostic trouble codes.
{2}. Clear the fault code using the OBD-II scanner
{3}. Cancel check engine light using a scan tool.

Method 3: Battery Disconnection Technique

What’s going on here?

The main thing you must remember when resetting the check engine light is that it can only be done in one way. There is no “tweak,” as some mechanics may both you to believe.

It must be done with the ignition on, but the car must not be running. (It will be stall after the reset.)

That being said, your job is to clear out the error codes from your check engine light to make it go away for good.

To clear the code, you will have to jump two terminals on your car battery.

You also must have a jumper cable. The one on your car won’t do. It must be one that you got or a car battery jumper box.

Start by disconnecting the battery. It’s the big terminal on the side of your car battery.

Next, connect the jumper cable—or if you don’t have one, the other end of the positive cable—to the positive terminal on the battery.

Connect the ground end of the jumper cable to the negative terminal.

Next, push down on the door lock switch in your car’s driver side. This will turn the ignition on.

Method 4: Turn Ignition on and off

3 times Starting the ignition and smoothly turning it off (and back on) three times will fool the car into thinking it has shut off because of an electrical malfunction. It will reset the check engine light and give you enough time to drive home.

Here’s the trick: Don’t turn off your engine on the fourth attempt since you’ll rev the engine too hard and the check engine light would go back on.

You can use this technique to turn your check engine light off on 2008 Toyota Prius. This car has an EFI (electronic fuel injection) which is why this might work on this model. When the check engine light is on, driving the car won’t affect it in any way. It will still run fine. Only mechanics can actually fix the problem.

You can use this method if you don’t want to go to a mechanic but would like your check engine light to go off. Maybe you want to let your mechanic surprise you. Maybe you’re going on a road trip and you don’t want to bother with the check engine light until you get back home.

Conclusion

The check engine light is an indicator that the check engine system is not working properly.

If the light comes on occasionally and goes away, you can wait to get the problem checked. The car will run fine with the light on.

However, if there is an error in the check engine light, you must get it repaired immediately.

Your car senses errors via the sensor and sends the information to the computer systems of your car.

If there is an error, the computer will show the error code in the check engine light.

You can try resetting the computer code in the check engine light by disconnecting the battery, loosening the gas cap, and waiting a few minutes.

If the check engine light remains on after you have reset it, you have an issue on your hands.

It’s best to get the vehicle checked by a reputable mechanic, because the problem could be due to a defective component and not just the sensor.