Computerized Diagnostics in Montgomery

The Check Engine Light

One of the most misunderstood indicators on your dashboard is the check engine light. The check engine light can come on with no warning and with no explanation. When the check engine light comes on it can be a frustrating experience due to the fact that this indicator can illuminate for many different reasons. The check engine light can come on for any car problem from a loose gas cap to a seriously misfiring engine. Ignore the warning and you could end up damaging expensive engine components. The check engine light can also be a sign that your car is getting poor fuel economy and emitting higher levels of pollutants as would be the case with a failure of one or more oxygen sensors. It can also mean that the check engine light itself is malfunctioning and that there is nothing actually wrong with the vehicle.

What the Check Engine Light Means

Expert Check Engine Light Advice in Montgomery

The check engine light is part of your automobile’s diagnostic system. Since the 1980s, computers have increasingly controlled and monitored vehicle performance. The vehicles computer system is responsible for regulating such variables as engine speed (RPM), fuel mixture and ignition timing. In some cars, the computer also tells the automatic transmission when to shift. If your automobile’s diagnostic system finds a problem in the electronic-control system that it can not correct; the computer will turn on a yellow warning indicator light that’s labeled “check engine”, “service engine soon” or “check powertrain”. Or the light may be nothing more than a picture of an engine, known as the International Check Engine Symbol, which may or may not include the word “Check”.

When your vehicle’s diagnostic system finds a problem, in addition to turning on the check engine light, the computer stores a “trouble code” in its memory that identifies the source of the problem. This code can be read with an Electronic Scan Tool or an Auto Diagnostic Computer. The Auto Diagnostic Computer or Electronic Scan Tool alerts the technician as to what problem has occurred and what area of the vehicle needs to be inspected.

The check engine light can be illuminated for various reasons. Some of these reasons can be minor; however, the check engine light should never be ignored due to the fact that some issues can lead to major mechanical failure. There are some common causes for the check engine light to come on, but without reading the vehicle’s computer system, you will not be able to properly diagnose the problem. It is always best to have the actual problem diagnosed by a certified professional with the proper diagnostic equipment for your vehicle.

Five Common Malfunctions That Can Trigger the Check Engine Light

•Gas Cap – a loose gas cap can actually cause fuel vapors to escape from the car and confuse the fuel system. This can lead to reduced gas mileage and increased emissions. If your gas cap is loose or not screwed on properly, tightening the gas cap can eliminate the problem. Also, check your gas cap for any cracks or improper fit.

•Oxygen Sensor – the oxygen sensor is located in your vehicle’s exhaust and it monitors the unburned oxygen from the exhaust. The oxygen sensor carefully monitors the amount of oxygen remaining from your fuel after combustion occurs and it helps monitor how much fuel is burned. Some fuels are considered “rich” meaning they have less oxygen left over than the typical ratio of air to fuel. Some fuels are considered “lean” which means they have to much oxygen remaining after combustion. Both of these scenarios can negatively effect your vehicle and the environment. Your automobile’s oxygen sensor monitors the ratio of air to fuel and makes adjustments to keep your car running efficiently. Over time, an oxygen sensor can get covered in oil ash and it reduces the sensors ability to change the oxygen and fuel mixture. A faulty sensor means it’s not providing the right data to the computer and causes a decrease in gas mileage and increase in emissions.

Most cars have between two and four oxygen sensors and the code received from a diagnostic scan tool will tell the technician which sensor needs to be replaced. Typically replacing an oxygen sensor is not a costly repair, however, if you do not have an oxygen sensor replaced in a timely manner, it can lead to a much more expensive repair involving the catalytic convertor.

•Mass Air Flow Sensor – the mass air flow sensor tells the vehicle’s computer how much fuel to add to the engine based on how much air is coming from the engine after combustion. Typically, a mass air flow sensor reading can actually be caused by the vehicle’s air filter. If the air filter was not installed properly, if it becomes dirty or if it hasn’t been changed in a while it can give a false reading to the mass air flow sensor. You should have your vehicle’s air filter changed on a regular basis. It is important to have this issue inspected by a professional technician because a problem with your mass air flow sensor not only reduces your vehicle’s gas mileage, but it can increase emissions and also cause your car to stall out.

•Spark Plugs – the spark plug seals the combustion chamber and provides a gap for a spark to jump across and initiates combustion in your engine. A failing spark plug can cause a misfire in your spark plugs, leading to less power in your car, sluggish performance and ultimately it can damage your catalytic convertor. If a spark plug is failing, your check engine light will typically blink on and off. It is important to have a spark plug problem corrected immediately to eliminate the possibility of further damage to your vehicle.

•Catalytic Convertor – the catalytic convertor works to reduce exhaust gases. It converts carbon monoxide and other harmful materials into harmless compounds. If your catalytic convertor is failing it stops converting carbon monoxide and other harmful compounds into less harmful compounds. When your catalytic convertor is failing you’ll notice a decrease in gas mileage and your car won’t go any faster when you push the gas pedal. When the catalytic convertor fails completely you will not be able to keep the car running. The main cause for a failing catalytic convertor is the previous listed issues, but it shouldn’t fail if you’re keeping up on regular maintenance.

Get Expert Advice on Your Check Engine Light

The check engine light can be caused by a variety of car problems. The best option for finding the reason behind the warning light is to have the professional technicians at Performance Auto Repair connect our state-of-the-art diagnostic equipment to your vehicle’s computer and inform you what the “trouble code” actually means.

Call Performance Auto Repair of Montgomery today at (334) 245-6600 and schedule an appointment to diagnose your check engine light.

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