Table of Contents
Check Engine Light
The check engine light is a signal that alerts drivers about possible problems with their vehicle’s emission system. The ECM (engine control module) monitors sensors in the vehicle, which monitor various components in the emission system including oxygen sensor(s), ignition timing, fuel injector pulse width, camshaft position(s), and intake air temperature sensors, etc. If a bad condition is detected by the ECM, then it will alert the driver with a check engine light.
This can be done through an onboard computer system that can detect certain trouble codes, or through external sensors such as OBD II (on-board diagnostics) to detect faults with the ECM. In this case, the vehicle’s onboard computer systems will check various components in the emission system and can give out a red light if there are any problems.
The check engine light is usually located near the tachometer or speedometer on most vehicles.
A common misconception is that if there is a check engine light, the car should be taken in to have the problem fixed. This is not the case and the “Check Engine Light” can harm your car’s performance and other components.
A common misconception is that if a check engine light comes on, someone must come and fix it as soon as possible; this is also not completely true. Once you see a check engine light it does not mean that your car needs to be rushed into any shop or dealership for repairs; you may be able to save some money by being able to fix it yourself or by looking up how to find out what needs fixing.
The check engine light is a signal that alerts drivers about possible problems with their vehicle’s emission system. The ECM (engine control module) monitors sensors in the vehicle, which monitor various components in the emission system including oxygen sensor(s), ignition timing, fuel injector pulse width, camshaft position(s), and intake air temperature sensors, etc.
If a bad condition is detected by the ECM, then it will alert the driver with a check engine light. This can be done through an onboard computer system that can detect certain trouble codes, or through external sensors such as OBD II (on-board diagnostics) to detect faults with the ECM.
In this case, the vehicle’s onboard computer systems will check various components in the emission system and can give out a red light if there are any problems. The check engine light is usually located near the tachometer or speedometer on most vehicles.
How To Reset Check Engine Light:
There are three ways to reset the check engine light depending on the vehicle:
When checking your vehicle’s engine you should clean out the engine and remove carbon build up. This is done by removing the spark plugs and pouring Seafoam in them. Then clean the MAF sensor with very hot water and soap.
Then spray carb cleaner or brake cleaner all over the insides of your engine, making sure to get around hoses, belts, and all openings of your engine. You can also use a shop vac with a brush attachment on it to clean out any carbon build-up, but that may be more time-consuming than necessary for some people.
Then spray a small amount of engine oil on the spark plugs to get them nice and moist, not wet. Then reinsert the spark plugs into their respective plug holes and start your engine up. This will help clear out carbon build up in the cylinders of your engine and get rid of any carbon deposits in the cylinders which would affect the performance of your vehicle.
This can lead to better fuel economy, horsepower, torque, and a more efficient combustion process by generating less heat.
If you notice that your check engine light comes on while driving after you leave your vehicle overnight or while you are away from it for a long period (more than a day) then you might have a faulty gas cap.
You should try tightening the gas cap and then see if the light goes away. If it does not go away, you will need a new gas cap. You can get one at any Auto Parts store or Walmart for about 3 dollars. A faulty gas cap can also be an indicator of there is a vacuum leak, that the O2 sensor is on its way out, or even though it is less likely that your catalytic converter is going bad (although it could still be).
Why Does My Check Engine Light Come On And Off?
You might notice that your check engine light comes on, flickers, and then goes off several times as you drive. This is most often caused by a faulty O2 sensor or catalytic converter. If the condition persists then you need to replace the O2 sensor or catalytic converter because it will burn out sooner or later due to the accumulation from it working overtime.
This problem can lead to reduced fuel efficiency, worse gas mileage, rough acceleration, and poor performance on long highway trips. Follow these steps if you are experiencing this problem:
- Inspect the connections of your oxygen sensor & catalytic converter to make sure they are not leaking. If they seem okay then replace them both with new ones.
- Inspect the wiring harness on your catalytic converter to make sure there are no cracks or broken wires. And if you do then replace it.
- Inspect the connection of your O2 sensor to make sure that it does not have any foreign objects in the connections (such as leaves or twigs). If you find one then remove it and clean out the inside of the sensor with a wire brush. Then replace this with a new oxygen sensor.
- Inspect your plugs, wires, and connectors for any corrosion, cracks, or pinched connections, and replace them all if necessary.
- Make sure that the wiring to your fuel injectors is intact. Also, inspect your ignition coil and spark plugs for cracks or damage and replace them if necessary.
- Make sure that all of the vacuum lines, hoses, and air intake tubes are clear and not collapsed. Also clear out the mass air flow sensor with a vacuum system tool, by removing any carbon build-up in the intake manifold, then use compressed air to blow out any debris that is in there. Make sure that all of the vacuum lines are intact & connected and replace them if necessary.
- Inspect your throttle body for leaks, broken or loose butterfly plates, or accumulated debris. A faulty oxygen sensor or catalytic converter would lead to more frequent check engine light flashing as well as reduced fuel efficiency, and a rough idle.
If you have recently replaced your catalytic converter then you will have to reset the check engine light by removing it from the vehicle and shaking it until it resets. This is easily done by disconnecting the battery for about 15 seconds before turning your vehicle on so that all of the electrical components are de-energized.
What Causes Check Engine Light To Come On?
If your check engine light comes on when you are driving then it means that there’s a problem with your catalytic converter or oxygen sensor. But if the lights come on randomly it can be indicative of a dirty fuel filter, a cracked IAC valve, or an air leak from the intake manifold or intake tubing.
The check engine light usually flashes because there is something wrong with one of these sensors, so carefully inspect these parts to make sure that they do not need to be replaced before you know for sure what exactly is the cause of the problem.
If your check engine light only comes on occasionally then your catalytic converter or oxygen sensor needs to be looked at closely since there might not be a problem with them.
How To Check Engine Light Codes Without A Scanner
If you have a check engine light that comes on when you are driving then the best and simplest way to check what the problem is by using an OBD II code reader. These are extremely cheap and you can buy them at any auto parts store or Walmart for about 25 dollars.
Then simply connect the reader to your OBD 2 port which is located under the dashboard of your vehicle and it will give you a read-out of all of the trouble codes. Code readers are really easy to use, but if you need more help or would like to know where exactly this code reader port is located then see my article on where everything is located in your car.
Common Problems With Engine Light Codes
If you get something other than P1-16, P0106, P0112, or P1399 on your engine code reader then you most likely have a problem with one of your oxygen sensors. This is a common problem with 99% of people that buy a new car but it is also common in older cars that have been sitting for too long.
The reason why they don’t display any codes is that they were never installed correctly and they require simple adjustments to make them work correctly again.
What Is The Most Common Reason For Check Engine Light?
There are several different causes for the check engine light to come on, but one of the most common reasons for this to happen is when the gas cap is leaking due to wear or corrosion. To make sure that this is not your problem you should inspect your gas cap and see if there’s any damage on it or if it has any cracks at all.
If you notice that the gas cap does not work correctly then you can get a new one at any auto parts store for about 3 dollars. Simply install it correctly and your check engine light should go off. If you still have a problem then you need to get it fixed because this could be a sign of an expensive problem down the road.
Is It Safe To Drive With Check Engine Light On?
If your check engine light is flashing you should continue driving until you get home safely but if you only get the check engine light occasionally then it’s okay to continue driving as long as there are no problems with your acceleration or power.
Always try to get whatever is causing the problem fixed because if your car has not been checked out by a professional mechanic then you might have an expensive major repair shortly. Even if the check engine light turns off it could happen again, later on, so make sure that everything gets checked out.
How Do I Know If My Check Engine Light Is Serious?
If your check engine light has been on for over a month try to get it checked out as soon as possible because it might be a sign of an expensive problem. Several different signs indicate that you have a serious problem with your car, so if the light comes on or begins to flash then this could be a sign of much more expensive problems down the road.
The first thing to check is how long the light has been flashing, if you notice this happening after 20 minutes of driving then there’s likely nothing wrong besides improper gas cap usage and if you are running late for work then this can be fixed.
A common sign of a serious problem is if the check engine light flashes after you have been driving for more than 20 minutes, especially if your car hesitates on acceleration. This could be an electrical problem with your ignition or spark plugs and it will require an expensive repair which should be done as soon as possible.
If the check engine light stays on when your car is idling and there is also a very noticeable decrease in gas efficiency then likely one of your O2 sensors has failed. The good news is that this problem can easily be fixed by replacing the sensor and getting it calibrated to fix any problems that are associated with this failure.
How Do I Clear Diagnostic Codes?
If you have an issue with your check engine light that has been on for a long time then you can clear the diagnostic codes yourself. The first thing that you need to do is remove the positive battery cable and the negative cable from your car because they will allow the computer to reset itself. Then take out all of the fuses that are located in the fuse box behind your steering wheel.
Then put in a new fuse and insert it into the fuse box, make sure that all of the wires from it go in their correct location so all of them go into one of your fuse slots. Make sure that you’re not inserting any wires backward or wires together as this can cause problems with diagnosing your engine light code.
Once you’ve replaced all of your fuses then wait about 15 minutes after putting them back in for the computer to reset itself then you can turn on your headlights and check if it resolves the issue. If it does then consider yourself lucky, otherwise you may have something more serious going on with your engine.