One Check Engine light; 1,400 reasons for it

It’s never a good feeling when you're driving down the road and your "Check Engine" or "Service Engine Soon" light flashes on. The light is part of your vehicle’s on-board diagnostics (OBD) system and can indicate anything from a quick fix like a loose gas cap to a major repair like a catalytic converter.

The Check Engine light can turn on for more than 1,400 different reasons, and in the coming months, we're going to share with you what some of those reasons might be.

Trouble code: P0300

One code that can set the onboard computer off is P0300, random misfire, which means the car’s computer has detected that not all of the engine’s cylinders are firing the way they should be. If this is a problem, the engine might be harder to start or might stumble and/or hesitate. Of all the reasons your Check Engine light can come on, this is one of the more serious ones. Imagine the literal equivalent of, "not firing on all cylinders."

A code P0300 may mean that your vehicle is experiencing one or more of the following:

• Faulty spark plugs or wires
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector(s)
• Burned exhaust valve
• Faulty catalytic converter(s)
• Stuck/blocked EGR valve / passages
• Faulty camshaft position sensor
• Defective computer

To properly diagnose a Check Engine light, bring your car to your preferred auto repair shop. At CARS of America,  one of our ASE-Certified Technicians would connect the system to a diagnostic scan tool and then retrieve the code (or codes) indiciating  which system is calling for help. The technician would then perform pinpoint testing to determine exactly what's going on. Depending on the issue, addressing the challenge right away can save big bucks down the road.

If you have any questions about your Check Engine or other dashboard lights, don't hesitate to contact me via email or by phone at 847-724-6724. I'm happy to help.

Brian Blohm is the Service Manager and Managing Partner - Operations for CARS of America in Glenview. He is an ASE-Certified Automotive Service Technician and ASE-Certified Service Advisor with more than 25 years of automotive experience. A graduate of Triton College with an associate's degree in Automotive Technology, he has continued his training and education with the Automotive Training Institute and RL O'Connor. You can reach Brian via email at brianb@carsofamericainc.com.