What does the Check Engine Light mean

The check engine light is a warning light that appears on the dashboard of a car when the car's onboard computer detects a problem with the vehicle's engine or emissions control system that needs to be addressed.  The light is typically shaped like an engine. While it can be alarming seeing an engine warning appear on your dashboard, especially if you've never seen it before, there could be a wide array of issues (some more serious than others)  that can cause a check engine light to come on.

What are the causes of the check engine light

There are many potential causes of the check engine light, and the most common cause can vary depending on the make and model of the car and the specific problem that is detected. Some of the most common causes of the check engine light include:

Loose Gas Cap: Your gas cap is loose, broken, or simply missing. Gas cap issues can reduce fuel pressure and allow fuel vapors to escape, reducing fuel economy and increasing harmful emissions.

Failing Catalytic Converter: Your catalytic converter can eventually clog with material, especially with higher mileage vehicles. The catalytic converter is a vital part of the emissions system, removing toxic carbon monoxide. A failing or clogged catalytic converter can severely impact fuel economy and vehicle performance.

Fouled Spark Plugs or Spark Plug Wires: Over time you will eventually need new spark plugs or spark plug wires. Your spark plugs create a hot spark that ignites the air-and-fuel mixture in the cylinder, allowing your engine to start and run. Faulty spark plugs or spark plug wires can cause your engine to misfire, reducing fuel economy, performance, and even prevent it from running altogether.

Faulty Oxygen Sensor: Due to long exposure to hot exhaust gas, your oxygen sensor might need replacing. The oxygen sensor provides vital air-fuel mixture information to the ECU. A faulty oxygen sensor can cause your vehicle's computer to supply the engine with too much or too little fuel. An engine with too little fuel is at risk of total engine failure, and an engine with too much fuel will create excessive smoke and odor.

Faulty Mass Air Flow Sensor: When exposed to dirty or particle-rich air, the Mass Air Flow (MAF) sensor could fail. Like the oxygen sensors, the MAF sensor measures the amount of air entering the engine and helps ensure the proper air-fuel mixture. A faulty MAF sensor can cause your engine to misfire, ultimately causing poor fuel economy, performance, and potentially more unnecessary damage to your engine.

These are just a few examples of the many potential causes of the check engine light. Whether your issue is a problem with the car's spark plugs, fuel system, or exhaust system, or something as minor as a loose gas cap. In some other cases, the light may indicate a more serious problem that requires more extensive repair work.  It is important to have the car checked out by a mechanic if the check engine light comes on, as the cause of the problem will need to be identified and repaired in order to prevent further damage to the car.

If the check engine light comes on, here are a few steps you can take:

Check the gas cap: One of the most common causes of the check engine light is a loose or damaged gas cap. Check to make sure that the gas cap is tight and in good condition. If the gas cap is loose or damaged, tightening it or replacing it may turn off the check engine light.

Check the engine: If the gas cap is not the cause of the problem, you may want to check the engine for any visible issues, such as leaks or loose hoses.

Have the car checked out by a mechanic: If the check engine light does not turn off after you have tried the above steps, or if you are unable to identify the cause of the problem, it is important to have the car checked out at your local independent repair shop by a BMW specialist as soon as possible. The mechanic will use diagnostic equipment to identify the cause of the problem and recommend the appropriate repairs. Ignoring the check engine light could lead to further damage to the car's engine or emissions control system, which could be more costly to repair.

What does a blinking check engine light mean?

If the check engine light is blinking while you are driving, it is important to take immediate action. A blinking check engine light indicates that there is a serious problem with the car's engine or emissions control system, and continuing to drive the car could cause further damage. Here are a few steps you should take if the check engine light is blinking while you are driving:

Pull over and turn off the car: If possible, safely pull over to the side of the road and turn off the car. Continuing to drive the car could cause further damage to the engine or emissions control system.

Have the car checked out by a mechanic: It is important to have the car checked out by your local independent BMW repair shop as soon as possible if the check engine light is blinking. Their BMW trained mechanics will use specialty diagnostic equipment to identify the cause of the problem and recommend the appropriate repairs.

It is not safe to continue driving the car if the check engine light is blinking, so you will need to have the car towed to your local mechanic shop. Ignoring the problem could lead to further damage to the car's engine or emissions control system, which could be more costly to repair.

Resetting the check engine light

There are a few steps you can take to reset the check engine light on your car:

Fix the problem: The check engine light will often come on if there is a problem with the car's engine or emissions control system. In order to reset the light, you will need to fix the problem that caused it to come on. This may involve repairing or replacing faulty parts, such as spark plugs or oxygen sensors.

Use a diagnostic tool: Many modern cars have diagnostic systems that can be accessed using a special tool. These tools can be used to reset the check engine light and to access diagnostic information about the car. While these tools may temporarily clear the check engine light from your dashboard, the light will reilluminate soon if the underlying issue causing the light to come on is not addressed. 

It is always a good idea to have the car checked out by a mechanic if the check engine light appears intermittently or stays on.  An experienced BMW mechanic can use diagnostic equipment to identify the cause of the problem and recommend the appropriate repairs. Remember resetting the check engine light will not fix the underlying problem that caused it to come on. The light may come on again if the problem is not properly addressed.