Check Engine Light Reset Itself

Will the Check Engine Light Reset Itself After the Problem Is Repaired?

In Engine by 10 Comments

The dashboard has a set of lights that inform the driver when there is an electrical problem.

You will have indicators, headlights, a fuel gauge, and the engine light. There are those scary moments when the engine light remains on, and the question is, will the check engine light reset itself?

The engine light could reveal a minor complication or something major that, if not repaired, could lead to more costs and repairs.

Will the Check engine light reset itself?

The check engine light will reset by itself after you repaired the problem in most car models. But it’s a little bit more complicated than that.

The problem is that it can take a lot of time because the car is doing a lot of checks each “cycle”. A cycle is when you start your car cold and drive it until it is warm and then until you are done with your driving.

If you are sure that you have fixed the problem causing the check engine light, the engine light will reset itself after 10-20 successful cycles and as you can imagine – 10-20 successful cycles can take a lot of time. Therefore it’s much easier to reset the check engine light with an OBD2 scanner.

If you want to reset the check engine light with an OBD2 scanner you can follow this guide: How to reset check engine light.

Reset the onboard diagnostic computer

Modern cars have an onboard computer that diagnoses car problems. If you have fixed the problem, but the light persists, you will need a scan tool like an OBD reader.

Connect the scan tool to the onboard diagnostic connector. This should be found under your steering wheel. Turn the ignition on and press the “read” button on your scan tool. You should be able to read a set of error codes. Write these for future reference.

Related:  Engine Mount Symptoms, Location & Replacement Cost

Once you are done, press the erase button on your scan tool, and this will clear them. The scan tool is an easy way to get a response to queries about whether the check engine light will reset itself.

Switching the ignition on and off

While your car is motionless, turn the ignition on and off with a second lag time. Repeat the process three or four times and then drive a short distance to see whether the engine light goes off. If not, try disconnecting your battery.

Disconnect battery terminals

Battery Terminals

If you want to reset the electrical components in your car, you can first turn off the ignition and then disconnect the battery cables. A pair of pliers or a wrench is useful for this. There is often some charge left in the battery electrical system, and you can drain this power by pressing the car horn for 30 seconds.

Wait for 15 minutes before reconnecting your car battery terminals. The engine light should have reset itself for most cars, but if it persists, it could mean that your car has other serious issues that need mechanical assistance.

Driving the car until it goes off

Most cars have a self-correcting mechanism for resetting the engine light. The simplest way to reset the engine light is to drive the car with the light on for several miles.

The onboard computer will detect the problem and turn off the light. If you notice the engine light is still on after three days, then it is time you tried some of the methods showed above or take it for mechanical repairs.

Check out this article for more techniques to reset your check engine light.

Why you should not ignore the engine light

If you have seen this light go on the dashboard, please do not ignore it because it could lead to more serious problems. The onboard computer will rectify itself, and the light will eventually go off; but you will want to know why the light turns on.

Related:  Low Fuel Pressure Symptoms & Causes

Most modern cars have onboard diagnostic systems. This system consists of a car computer that monitors various sensors in multiple car components. If your car has a problem, the sensors will capture this problem and send the information to the onboard computer that will then display a warning light on the dashboard.

The engine light has a different color depending on the make of the car. Some are orange, red or yellow; while some have the word, check engine. The light can either flash or remain on for some time. If it is flashing, stop what you are doing, pull over, and shut off the engine.

Loose gas cap

This is one of the most common human error reasons for the engine light remaining on. Gasoline powers your car and after fueling up, you may forget to replace the gas cap. This can be extremely dangerous because gasoline is highly flammable.

You will know that the problem is with the gas cap if the check engine light turns on immediately after filling up. Stop the car immediately and tighten the gas cap. If it is lost, do not drive without one.

Oxygen sensor

Oxygen is a crucial component in the burning of gasoline in the engine. The oxygen sensor is useful for measuring the amount of unburnt oxygen in the exhaust system. When the oxygen sensor is not working, the car burns more fuel, and this will eventually destroy the catalytic converter or spark plugs.

The check engine light will come on when the oxygen sensor starts malfunctioning. Head to a service station to get it replaced if you do not want your car to fail the emission test.

Related:  Car leaking fluid: 6 Different Liquids that may drip from your car

Spark plug/ignition coil problems


Will the check engine light reset itself if you have bad spark plugs? The answer is no. Spark plugs get their electricity from the ignition coil, and this enables them to emit a spark that ignites the air and fuel mixture in the cylinders.

If the ignition coil is faulty, the check engine light will turn on. Old and expired spark plugs will cause the engine to misfire, and this will lead to you spending more on fuel. Taking your car for regular services can eliminate this.

Bad alarm systems

Not all alarm systems are effective. Some cheap makes can drain your battery charge, and some can trigger the engine light. In the worst case, they can prevent your car from starting. If this is the case, you can remove the faulty alarm and replace it with a better one – although this can be costly.

Dead battery

Sometimes the cause of all your dashboard problems could be that your battery time has expired. You will first need to determine whether the battery can be recharged or you need a new one. A good battery should last you 5 to 7 years.


The question of whether the check engine light will reset itself is often asked by many drivers. It can be irritating driving a car with a flashing check engine light. The first thing you should do is to pull over and check whether anything is wrong with your engine components.

If all is good, the light should go off after driving a few miles. You can also use a scan tool to reset the onboard computer. If you do not have one, disconnect your car battery and wait for 15 minutes for it to reset.

10 thoughts on “ Will the Check Engine Light Reset Itself After the Problem Is Repaired? ”

  1. Hello I have a mini chilli pack 15 years old, I was driving home from work and it felt very sluggish and could only do 20 mph , I have now had new spark plugs and coils fitted , the car is now working again , have driven it around and it seems to be fine, unfortunately the engine light remains on , and m.o.t is due soon , please can you e mail me to tell me how I can try and get rid of this light.
    Many thanks

    Lianne Robertson

  2. I change my number 2 sensor downstream on my 2007 Hyundai Santa fe how low for the check engine light to go off.

    1. My Ford Fiesta 2006 the enjin light keep on coming on. Sometimes it stays on other times it goes off. When the enjin light was on the car also shattered. The car being in for a water problem for the last 3 months. They fix the one problem a week or two latter same thing happen again another water problem. Please advice what wrong.

      1. Hi have a 2000 suburban 80000 miles changed battery all ok, drove car 167 miles then check eng. lite came on,drove car for 101 miles still on, mech says drive it, but it wont pass insp with lite on? Thanks

  3. I have a peugeot 206cc i have changed spark plugs,coil packs it does not have catalyitc converter i have removed it but still the car shows antipollution faulty and catalytic converter faulty the car shakes when driving and its consuming more feul engine light goes on and off…please help

  4. Hi my name is Mary I had my engine light on for 3 weeks took car in for diagnostic test light is off now do I still need to fix my car

  5. My 2007 Pontiac G5 has check engine light on, The only code is: PO463 . It came on when I bottomed out over a curb and I could open the gas cap and tighten it and the light would go off for a while and now it always stays on but I also noticed that since the light is on my factory installed auto start does not work, the head lights flash but it doesn’t start. I removed the negative battery terminal and reset the on board computer the check engine light went off and car started right up with auto start and ran for 1 or 2 minutes and then stalled out. The check engine light was back on and auto start wasn’t working again. I can not seem to get a mechanic to listen to what I’m saying about the car. They just tell me I need a new fuel pump and that my fuel tank needs to be removed in order to do this which will cost me between $750 & $1,300 for parts and labor but I do not want to pay all that money if it’s an electrical issue but no one will even put it on a lift and inspect the underside of it and my registration expires the end of this month, 2/29/20 and I am disabled on fixed $ is there any other solutions to pass inspection without paying so much money?

  6. We have a 2011 plate zafria which had an egr value problem it’s a diesel we brought a brand new one fitted it and still the light is on and code is showing p400 we knock it off and it comes back on once the car goes cold! Do we need to take it for a big run to have the car register it’s been fixed? It’s due an MOT and we have done all that’s needed and we don’t want it to fail for a code that we have already put right many thanks .

  7. Hi
    I have a 2006 cadillac cts 2006. Two sensors were changed p0056 and p0057. But we forgot to reset the ecu. The check engine light came on. We reset the ecu, let it idle for 30 minutes, took it for a good drive, went different speeds the engine light stayed off. When I went to drop off my mechanic I said wait, this is the test, I turned my car off waited a few seconds and turned it back on and with in a minute the engine light came back on. We ran the diagnostic test and under DTC under fault it’s Ed 01 under pend it’s a 01 when we scan through it said NA. We ran the IM and the catalytic converter was not ready, the Evap not ready and the O2 sensor p0056 not ready what can be the problem. We can’t understand why the engine light is coming on but we get an NA reading.

Leave a Comment