Why is My Check Engine Light On?

Nothing quite triggers the same feeling of dread as your cars check engine light sparking to life. A lot of fear and uncertainty seems to orbit around this apparently innocuous little light, partly because no one seems to be sure what it means exactly.

Weve decided its time to end the check engine lights reign of terror. In our handy guide, we explain how these lights work, and explore some common reasons that they might switch on. Finally, we offer some practical tips in what you must do if this menacing small light makes its existence known on your own dashboard.

Exactly what is a Examine Engine Light and just why do WE ARE IN NEED OF Them?

A cars examine engine light is actually a diagnostic device – it lamps up whenever a cars up to speed computer issues one warning.

They come in many shapes and sizes, depending on the make, model, and age of your vehicle. Usually, the light is shaped in a pictogram of the engine, in amber or red, but can also be text reading ‘check engine or ‘service engine quickly. Examine engine lights routinely have two specific stages: regular, indicating a minor fault, and flashing, indicating a severe fault.

Modern cars self-diagnostic abilities are impressive, and they came about largely in response to a piece of 1991 legislation. In that 12 months, the California Air Resources Board required that all newly manufactured cars were equipped with an onboard emissions-monitoring system. Five years later, this monitoring system, called OBD-II (an acronym for ‘On Board Diagnostics) was applied through the entire US. Each program was fitted using a general connector and conversation protocols, so problems could possibly be diagnosed by any garage area with the proper devices. With OBD-II systems, the interface is always situated in the drivers footwell.

OBD-II displays many different facets of the cars operation, the primary areas getting:

  • Fuel shot
  • Ignition program
  • Auto transmissions

Individual producers may gather data on a complete host of extra components, but they are the fundamentals. This diagnostic program eliminated the need for an annual ‘tune up with the mechanic, since on board computers constantly adjust the combustion process by gathering data from a number of sensors throughout the vehicle, and using it to combine the correct amount of fuel with the right ignition timing, to be able to provide the most effective burn feasible. When complications are discovered by OBD-II, this sets off the illumination of the cars check engine light.

Just how do Check Engine Lighting Work?

Aswell as allowing gasoline to become burned even more cleanly and effectively, the OBD-II program created a fresh method for car complications to become diagnosed. When an OBD-II device is linked to a cars interface, the ‘mistake rules communicated could be interpreted with a mechanic. A couple of a lot more than 3,000 common fault codes, and they can indicate problems with anything from braking, to steering, to ignition, to suspension. Some cars actually monitor their personal wheel pressure, and if you elegant trying this technology out for yourself, you can even purchase your personal pressure monitoring package to become retrofitted to your automobile.

The ‘mistake rules that technicians may use to diagnose complications in your automobile also cause the illumination from the check engine light. Whenever a sensor detects a issue, this data is normally relayed towards the cars on-board pc; the relatively unimaginatively called Engine Control Device (ECU). Initially, the ECU interprets this mistake code as ‘pending. This implies maybe it’s a fluke, which resolves itself. Only when the ECU receives the same problem code on the next journey is a sign delivered to the dashboard leading to the check engine light to become illuminated.

The light continues to be illuminated so long as the mistake remains. If it goes away on its own, the light will only pull the plug on after three fault-free journeys. Computer savvy ‘car hackers sometimes use OBD-II tools to clear problem codes from the ECUs memory space when the examine engine light annoys them, but its better to avoid this plan and discover what problem has been recognized.

Common Factors Your Examine Engine Light can be on

Given that we know a little more about how check engine lights work, its time to run through some of the most common faults that trigger its illumination. If your cars check engine light has switched on, it doesnt necessarily mean one of these issues may be the culprit, but extra symptoms could help understand whats taking place – you may even have the ability to perform minimal fixes yourself.

You examine that properly – perhaps one of the most common factors that check engine lighting switch on is due to a loose gas cover. When youre halting for gas in a rush, you might not screw the cap back into place properly, or even pull away with the cap still sitting around the cars roof! Jokes aside, this apparently trivial issue can actually be quite damaging to a vehicle. Loose or missing caps allow gas vapor to escape from your gas tank, and prevent the gas inside from being kept a constant pressure. This prospects to wastage, a less efficient burn, and more emissions. When you first spot the check engine light illuminate, draw over and check your gas cover is properly set up – that is especially apt to be the issue if the light occurs immediately after you fill. If the gas cover is loose because of harm, or youve were able to misplace it entirely, a universal substitution can be experienced for only $15 from your local auto parts store, or online.

Another common trigger for the check engine light is usually a malfunctioning oxygen sensor. These sensors help your car burn gas cleanly and efficiently, by monitoring the amount of unburned oxygen in its exhaust system. With this information, the optimum combination of surroundings and fuel could be fed into the engine to improve effectiveness. A failed air sensor isnt essential for your vehicle to run, nevertheless, you might observe that its guzzling even more gas than normal. The receptors also help reduce imperfect combustion, which creates of soot and poisonous carbon monoxide. An upgraded oxygen sensor could be had for about $175, and labor costs may differ.

  • Ailing Catalytic Converter

The catalytic converter is normally another common culprit when check engine lighting seriously. Its an exhaust program component in charge of transforming the dangerous substances sometimes created during combustion into safe, inert ones:

  • Poisonous carbon monoxide is definitely converted into inert carbon dioxide
  • Nitrogen oxides, greenhouse gasses which can be harmful to humans and cause smog, are converted into harmless nitrogen and oxygen

These two reactions work in tandem with one another. If a cars catalytic converter no longer works, chances are the vehicle will surpass emission caps for these chemical substances. Changing a catalytic converter could be a pricey affair, varying between $200 and $600. You might help boost your converters life expectancy by executing regular car maintenance – this ensures it isnt coping with even more pollutants than typical, or subjected to dangerous temps.

  • Spark Plug or Ignition Coil Complications

Spark plugs and ignition coils are another potential culprit inside our line-up. Ignition coils generate energy, that your spark plugs after that make use of to ignite energy inside a gas engines cylinders. If these parts arent working because they should, energy isnt being burnt since it should, and you may expect problems obtaining the car began, backfiring, stalling, poor energy economy, and excessive engine noise. Luckily, new spark plugs only cost around $15, and having them installed is a simple affair. If youre fairly DIY savvy, you can even replace a spark plug yourself at home.

Bear in mind that this wont be an issue if you drive a diesel car, since diesel engines rely entirely on compression to ignite their fuel – they dont have ignition coils or spark plugs.

  • Faulty Spark Plug Wires

Spark plugs themselves arent the only ignition system component that can cause the check engine light to change on – issues with the wiring may also possess the same impact. These wires carry out electricity through the ignition coils towards the spark plugs, permitting them to ignite the energy in the engine cylinders. Faulty cables dont conducts energy as well, signifying the spark plugs will occasionally neglect to ignite the energy. Symptoms of faulty spark plug cables consist of:

  • A drop in engine efficiency and power
  • Reduced energy economy
  • Louder idling

Replacement cables can be got for $50, which means this car concern shouldnt break your budget.

  • Failure from the Mass Air flow Sensor
check engine light

Another element that may illuminate the check engine light when its faulty may be the mass air flow sensor (MAS). As its name suggests, the MAS displays the quantity of air flow entering the engine. Like the oxygen sensor, part of this components job is usually to help make sure fuel is usually burned as cleanly and efficiently as you possibly can, by supplying the optimum air flow to fuel ratio towards the engine. With no MAS, an automobile will struggle at high altitudes where bigger volumes of surroundings must burn fuel because of lower air density. In case your MAS is certainly ailing, you will probably have trouble starting the car, reduced fuel economy, stalling, and excessive noise while idling. Purchasing a new MAF will set you back between $120 and $150, plus labor.

If you have experienced an aftermarket alarm installed in your car, this can cause the check engine light to illuminate if it isnt operating properly. Its simple enough to inform if an aftermarket security alarm is not executing since it should – it could:

  • Drain the electric battery
  • Avoid the vehicle from beginning
  • Activate from just a slight disruption, such as dropping leaves

If you suspect that a fresh alarm could be behind your check engine light coming on, it will probably need to be reinstalled.

Leaks inside a vehicles vacuum system can also result in the check engine light. Car engines naturally produce a vacuum as they operate, and this vacuum can be used to power brake boosters, windshield wipers, and several other accessories. It also helps direct harmful unburned fuel back into the engine, reducing emissions. This technology is particularly prevalent in cars from the 1980s and early 1990s – before electrical systems were capable of handling as many add-ons because they are today. As you may expect, leaks will be the most common vacuum program issue. The tubes that connect the intake manifold to several other components may become cracked as time passes, and sometimes have to be changed. If your vehicle has a vacuum leak you can expect an unusually high or fluctuating rpm when idling. New vacuum tubes cost just a few dollars each, nonetheless it could have a mechanic a while to locate the source from the leak.

  • Exhaust Gas Recirculation Valve Failing

Virtually every modern car has an exhaust gas recirculation (EGR) system, controlled by a valve. When the valve becomes clogged or otherwise fails, the check engine light will illuminate. We discussed the symptoms associated with this in an earlier blog entry. EGR valves can very often be removed, cleaned, and reinstalled to fix the problem – you can do this yourself or enlist the help of a mechanic. For a new valve, you can expect to pay around $125. Its vital that you have a working EGR valve to make sure your car fits emission hats and operates as efficiently as is possible.

Within an EGR program, exhaust gasses are aimed back to the engine, instead of sent right to the exhaust pipes. It has several benefits:

  • Any unburned energy in the exhaust gases is certainly sent back in to the engine for combustion. This significantly reduces the amount of gas being released into the atmosphere, and improves the engines fuel efficiency.
  • It reduces nitrogen oxide (NO) and nitrogen dioxide (NO2) emissions. These harmful pollutants form spontaneously from the nitrogen and oxygen in the air when temperatures are hot enough – as they are inside an inner combustion engine. Channeling these gases back to the engines cylinders decreases the percentage of air in the cylinder, producing for a smaller sized level of combustible gas. This decreases the quantity of high temperature released as the engine operates, reducing on the forming of nitrogen oxides.
  • Flat Battery pack

A cars electric battery has a great deal riding onto it – if the electric battery is drained plenty of, the car wont actually make it out of the parking lot! Faulty or smooth batteries are another perfect suspect when it comes to illuminating the check engine light. Symptoms of a faulty battery include:

  • A slower than typical crank when starting the car
  • Temperamental electronic equipment, such as power windows or windshield wipers
  • A separate dashboard light in the shape of a electric battery illuminates
  • Hook rotten egg smell emanating in the hood
  • A distended electric battery case

If the electric battery proves faulty, its likely that youll need to purchase a brand-new one, at a price of around $100. If its merely out of juice, recharging it yourself is rather straightforward. You can buy a car battery pack recharger for less than $15, which pulls power from any electric outlet and pushes it in to the electric battery. When recharging, be sure to:

  • Disconnect the battery before you begin, to minimise the risk of shocks
  • Disconnect the negative terminal first, and reconnect it last
  • Dont charge the battery if the terminals appear corroded or otherwise damaged

Dont Ignore the Light

If your car doesnt feel or sound any different than normal when the check engine light comes on, theres no need to instantly stop what youre doing and make a bee-line for the nearest garage, but we urge you never to disregard the light either.

As weve noticed, check engine lamps are sometimes lighted in response to pretty minor complications – a lacking fuel cover or dodgy spark plug. Actually if this is actually the case, disregarding the light can be an awful idea, because right now if a far more significant problem arises, so long as possess the check engine light to warn you that something can be incorrect because its busy complaining about something else.

engine light

Proper car maintenance is much like health maintenance – if you ignore minor problems, they can quickly become much worse. The check engine light is no exception to this rule, and if it remains illuminated for a few trips, have your car checked out even though you havent observed some other symptoms. This process can save you time and effort and stress over time!

How to proceed When Your Verify Engine Light Occurs

You might eventually need to look for the assistance of a reliable mechanic when your check engine light rears its unsightly head. In the meantime, however, there are troubleshooting steps you can take yourself to get to the bottom of your check engine light enigma:

  • Check the Gas Tank Cap

As mentioned earlier, a faulty, missing, or even improperly placed gas cover can illuminate the check engine light like xmas. If the cover is apparently set up, its often worthy of purchasing a brand-new someone to try. If this deactivates the light, great; if not really, youve got an extra cap.

You possess a few different alternatives for accessing these details: take your vehicle to a auto mechanic, stop by an auto parts store, or do it yourself. Each approach has its own pros and cons:

  • Visiting your Mechanic – Youll need to pay a diagnostic fee to use this service inside your typical shop, but an area mechanic will probably waive the charge if you consent to have the required work performed at that one garage area. This one-stop-shop strategy could possibly be the most convenient choice, and is probably best if you notice that your car feels or sounds different. This option is also your very best wager if the check engine light is normally flashing on / off, as this denotes a significant, rather than small, problem.
  • Visiting an Auto Parts Store – Most auto parts stores present free diagnostics in the hope that customers will buy any necessary parts right there and then. This option could save you money set alongside the auto mechanic, as you might find you can repair no matter the issue is normally yourself. Before your go to, make sure to check the shop can accommodate the make and style of your vehicle – some possess unique onboard computers.
  • Checking Yourself – On the other hand, you could invest in an inexpensive OBD-II scanner and check out the problem code for yourself. If you have an older car that regularly exhibits minor problems, this is a very sound investment. It can also be useful for figuring out the extent from the issue when youre on the run, or a long way away from your own regular mechanic or car shop.

After the problem continues to be identified, its a straightforward case of repairing the problem when you can, or searching for assistance from a reliable mechanic if its away from personal understanding.

Using an OBD-II Scanning device

Looking at which problem code has triggered your check engine light to illuminate can be a relatively basic treatment:

  • Find the equipment – Buy an OBD-II scanner and assure its appropriate for your vehicle. Some scanners can transmit info to your cellular device, producing them more accessible to use. This type of system will set you back around $15.
  • Locate the Connector – Your vehicle handbook should help with this. Look out for a 16-pin D shaped connector, usually located close to the steering wheel, and often in the drivers footwell.
  • Turn on the Ignition – Dont start the engine, but turn the key until the ignition switches on.
  • Launch the Diagnostic Software program – Start this program or program that was included with the scanning device, on your notebook, tablet, or smartphone, and follow the guidelines it offers.
  • Interpret the Rules – Most software program provides a numerical code, along with a conclusion about what this means.

Using these scanners might help you understand the problem – you might even be able to avoid a costly trip to the mechanic.

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