How do I reset the check engine light after it comes on? Many drivers seek solutions to this problem, especially if it happens frequently.
Two solutions to this problem: either visit a good and trustworthy mechanic or try to do it by yourself.
Visiting a mechanic is certainly the right way to go especially if you suspect and have symptoms of a bigger problem.
But what should you do if everything seems OK with your car, but the check engine light stays on or even worse, goes on and off at certain time intervals? What should you do if the check engine light goes on even after visiting the mechanic and making the repair?
Usually, this means frequent visits to the mechanic which can cost time and money. Not to mention the fact that maybe after a few visits, even the mechanic will shrug shoulders and tell you to drive like that. Each visit will cost you time and money as there is a charge (in most cases) for each diagnostic read and fault code clearing.
As a result, you can easily end up with lost time, money, and unresolved problems.
On the other hand, you can try to reset the check engine light on your own.
In this article, we’ll focus exactly on that and on some of the most common DIY ways to make a reset.
You can certainly do this on your own. The possibility of damage is minimal and even if you don’t succeed, you can always drive the car back to the mechanic.
All you’ll need is some goodwill, basic car knowledge, and some tools.
RESET CHECK ENGINE LIGHT IF THE PROBLEM IS SOLVED
Before we start, I’d like to highlight one thing almost all people tend to do.
That is to reset the check engine light and ignore the actual problem.
Have always in mind that the check engine light goes on for a reason.
The ECU (Engine Control Unit) constantly monitors most of the systems in the car. One of its main tasks is to tell you that there’s an error and signalize (among others) with the check engine light.
Sometimes it may be a minor twitch in one of the systems but it also can be a serious fault that needs to be solved right away.
Therefore, if the check engine light appears rarely, go ahead and do the reset procedure. Get the fault code and try to check the problem and possible causes.
Monitor if it appears after that and at what interval. If it’s a glitch in the system, then you’ve solved the problem and the check engine light won’t appear. I’ve had one of these situations myself, if you’re interested in how I solved the problem click here for a separate article on that topic.
If there is a serious malfunction, then a check engine light reset will not help and the light will continue to pop up.
On most cars, if the check engine light is constantly glowing, then the problem is the more minor meaning you can probably continue driving.
If it starts to blink, then the problem is worse. In this situation it is better to stop driving the car.
ON WHAT CARS SHOULD YOU ATTEMPT TO RESET THE CHECK ENGINE LIGHT?
Another point which I would like to make before you start to reset the check engine light.
Today’s cars are becoming more and more complicated regarding electronics.
They are, more or less becoming computers on wheels. This has its advantages, but from the maintenance point of view, it’s simply getting harder.
Upper-class cars (premium, luxury, performance cars, etc) tend to have complicated electronic systems that are intertwined in ways that can cause unpredictable side effects. They simply have more electronics on them.
Middle and lower class cars tend to have less complicated electric and electronic layout making them more suitable to reset check engine light on your own.
The main point here: if you drive a premium car with a more complicated electronic layout (read lots of gadgets multiple ECU-s or else), it's best not to try this.
Due to the complicated nature of the installation, there may be unpredictable side effects that will cause problems. Perhaps you’ll reset the check engine light, but you’ll damage something else.
In addition, these kinds of cars often demand specific diagnostic tools that are expensive and complicated.
So, if you’re driving a “spaceship”, best leave this to professionals.
If you’re driving a medium or lower class car (read less complicated), go right ahead.
WHAT TOOLS WILL YOU NEED TO RESET THE CHECK ENGINE LIGHT?
OBD II SCANNER
This is the proper way to go. OBD II scanners have connectors that access the ECU unit on the car and make a readout of the faults. Basic ones can read fault codes and clear them.
If you don’t have one, you can buy a good OBD II scanner (depending on type, functions and your market). Of course, you have the professional ones, but they are both expensive and more complicated to use.
As mentioned the OBD II scan tool is essentially a tool that reads and clears fault codes.
You’ll probably be using the basic one which has an old school type screen (like a digital watch) and a set of buttons for navigating the menu. These are the most widespread and least expensive.
Of course, there are ones with LCD displays and more functions, but these tend to be more expensive and are usually meant for professional use.
OBD II scanners work on a basic “YES” or “NO” principle and the navigation is mostly up, down left, or right through the menu. If you’ve played Tetris, you’ll know how to do this, trust me.
Here we’ll state a basic principle, it depends on the type of scanner, but you should be able to get the idea.
1. Find the OBD II connector
Most of these connectors are hidden behind a plastic hatch or less visible places (like above the foot pedals).
Each car model has a location of its own. I would recommend Google it to save yourself some time and wandering around. Believe me; some manufacturers have made it like seeking lost treasure.
Most common places would be under or around the steering wheel column, above the foot pedals, or inside the fuse box.
2. Connect the OBD II scan tool
This connection is universal, so any OBD II tool should fit. The connectors are easily recognizable, something like you would find on a computer.
Before pressing down on the connector, make sure it is properly seated to avoid damaging the pins and connectors on both the car and the scan tool.
3. Turn the ignition key
DON’T CRANK THE CAR!!! Just turn the ignition and the lights on the dashboard will go on. This gives power to the ECU making it able to communicate to the OBD II scan tool.
4. Let the scan tool work (connecting and scanning).
You will see a message on the display where the scan tool is reporting that it’s establishing communication with the car ECU. If everything is OK, it will start to scan. This may take a few minutes. Let it be and don’t interrupt.
If it stalls, check the tool-to-car connection once again.
5. Read the error codes
Once the scanning is finished, the error code(s) will appear. Error codes are expressed in letters and numbers (like P0171, P0162, etc) and in some diagnostics, a few words of explanation are added.
6. Find the meaning of the error code
My advice for this part: if you conclude that the malfunction is more serious, it's best to deal with it immediately. In this case, trying to reset the check engine light is just a waste of time. The moment you restart the car, it will light up again.
If it’s temporary, then you’ll probably be able to solve the problem.
Maybe the best example regarding when you should reset the check engine light is a faulty lambda sensor error code.
It may be caused by low-quality fuel, excessive air in the gas tank, or else which are basically one-time mishaps.
When you change the gas station or vent the gas tank via the gas tank cap the problems will be gone.
In this situation, a DIY reset is very welcome.
7. Reset the check engine light
In the menu of the OBD II scan tool, you’ll find menus that will let you access reset functions.
Most OBD II tools work on the same principle, so just use the navigation buttons and work it out. Usually, it’s not complicated.
Press the reset button and you’re finished.
8. Disconnect the OBD II scan tool and turn off the ignition.
9. Start the car. If everything is OK, the check engine light warning should go away. Since this is a reset, best let the car idle for some time so the ECU can collect new data.
If everything is OK, the check engine light should go off and stay that way.