Check Engine Light

Lithia Motors, Check Engine Light
Help! My Check Engine Light is On, What do I do?
A few things can fill a modern motorist with dread and chill your bones right down to the narrow, like the feeling you get in the gut of your stomach when the dreaded "Check Engine Light" comes on. What does it really mean and why do we have that darned thing? Sometimes, the light just appears mysteriously, and you think, 'My check engine light is flashing' or 'My check engine light is blinking' or worse yet, 'My check engine light is staying on and glaring at me and it won't go off!' But what does it mean when the check engine light comes on, and more importantly, what should you do? What are the reasons for the check engine light? Can you still drive when the check engine light is on? Well, we're here to help to answer these perplexing questions.  

The annoying thing about your check engine light is that there's no way to know if the problem is minor or major until your mechanic hooks up a scan tool and reads the codes that caused it to come on. In any event, once your check engine light comes on, you should find out what is wrong as soon as possible. If the engine seems to be running normally (not running rough or misfiring) you can probably continue driving so that you can take the car in for service. Know that if you live in an area that requires vehicle emissions testing, your car will not pass an emissions test if the check engine light is on or there are any live trouble codes in the OBD memory. Remember that ignoring the check engine light can lead to more costly repairs later. 

First, Relax.

When the check engine light comes on, it doesn’t mean you have to pull over immediately and abandon your vehicle. But it means you should get the vehicle checked as soon as possible. By ignoring that little amber light that either says “check engine” or shows an icon of an engine, you could damage expensive components of your car. Also known as the malfunction indicator lamp, the check engine light is an indication from the car’s engine computer that something is amiss. It’s part of your car’s onboard diagnostics system. Besides turning on the amber light, your car’s computer stores a “trouble code” in its memory which your Lithia auto mechanic can access to figure out the source of the problem. The auto industry created a standardized system for diagnosing trouble codes called OBD-II back in the late 1990s that created trouble codes that can be read through the use of a universal connector.

Reading the Codes

To read the codes, your mechanic plugs a scan tool or code reader into the 16-pin OBD-II diagnostic connector usually located under the dash near the steering column. The scan tool displays the specific codes that caused your check engine light to come on. Software (and hardware) that is required to read the codes can vary depending on the year, make and model of your vehicle. You can check these codes yourself by buying a code reader from any auto parts store or online that connects to the Onboard Diagnostics (OBD) port. You can find all the code meanings online, or use a Code Reader app on your smartphone. But just reading the codes is not enough. All makes and models of cars are not the same and it takes a trained technician to know what those codes really mean to your specific car and how to make proper repairs.

Common Reasons for a Check Engine Light to come on

Generally, when the check engine light comes on it is because a problem occurred in the engine control system that affects emissions. Depending on the problem, the lamp may come on and go off, it might remain on continuously, or flash. Some types of intermittent problems will make the lamp come on only while the fault is occurring. When the problem goes away, the lamp goes off. Other types of problems will turn the lamp on and keep it on until the fault is diagnosed and repaired.  

The most common reasons for the check engine light to come on include:
  • Tripping sensors for the gas cap
  • Oxygen sensor
  • Catalytic converter
  • Ignition coil
  • Purge control valve
  • Mass airflow sensor
  • Fuel injector
  • Thermostat
But whatever the problem turns out to be, don't ignore that little amber light and don't place a piece of black tape over it. 

What is the most common reason for check engine light?

Believe it or not, the number one reason why a check engine light comes on is that you have a loose gas cap. It keeps the whole fuel system under correct pressure. Inspecting and tightening the gas cap may make the check engine light go off.

Is it OK to drive with check engine light?

Generally speaking, yes. The check engine light is triggered when the car’s computer senses a problem in the operating system. Most common reasons that the light comes on include an oxygen sensor failure, loose gas cap, catalytic converter failure, mass airflow sensor failure, exhaust system leak, spark plug or ignition coil issue. While you can still drive the vehicle, suggest you take it in to run a diagnostic test right away.

Is a check engine light serious?

It can be. When the check engine light comes on, it means yout car’s computer senses a problem with your vehicle’s emissions or electrical system. A misfiring engine can overheat the catalytic converter, causing it to fail and that can lead to damage to the engine. Don’t ignore the check engine light. Take your vehicle in and have a technician run an OBD-II diagnostic scan to determine which error codes have been triggered.

What do I check when the check engine light comes on?

First, check your gauges to see if you have low oil pressure or if the car is overheating. If these issues are present, turn off the car immediately. Check the alternator and serpentine belt. Check the oxygen sensor. It measures unburned oxygen in the exhaust system. A faulty oxygen sensor can make your car burn more gasoline. Check the catalytic converter. A faulty unit can cause reduced fuel economy and can cause the car to overheat. If the mass airflow sensor goes bad it can damage the spark plugs, O2 sensor, and catalytic converter.

What does a solid yellow check engine light mean?

A solid yellow check engine light means you should have the car checked as soon as possible. A flashing yellow light may mean the vehicle is misfiring and that can cause poor performance and poor fuel economy at the very least. If the check engine light comes on, have your car checked by a certified technician right away. Schedule an appointment with your local Lithia Motors dealer.

Why is my engine light on but nothing seems wrong?

The check engine light may come on for a number of reasons and not all of them are serious. If it comes on while you are driving, don’t panic. Pay attention to how your car is behaving. Is the engine surging? Is it overheating? The problem could be as simple as that your gas cap is loose and needs to be tightened. However, the problem might also be serious and continuing to drive with the check engine light on can cause damage to your engine. Don’t ignore the check engine light. Have the car checked right away with a diagnostic scan at your local Lithia Motors dealer.

Today's cars are pretty smart. For many emissions problems that could cause the check engine light to come on, the car's onboard computer will often try to compensate by reducing power to the engine in order to reduce the risk of damage. You might not notice any difference in performance. However, you could be dumping unnecessary pollutants into the air by ignoring that little light.  

Sure, the little amber light with the engine icon could be something really simple such as a bad sensor or a faulty or loose gas cap. But it could also be something far worse. Either way, when your check engine light comes on, it means a trip to your local Lithia Auto Service Center to take care of the issue and get that little light turned off! Lithia Motors has your back. Our trained technicians will get that check engine light sorted and get you back on the road. 

Find a Lithia Auto Service Center and schedule a service appointment today.