“My check engine light is on. Now what?”

The ever-dreaded check engine light. When it’s illuminated, it means that something is wrong with your car. But what?

Generally, it means that the Powertrain Control Module (PCM) has detected a problem within your car. It can be something minor like a loose gas cap or something more sinister like a congested catalytic converter or failing sensor.

Whatever the reason, you’ll need to do a computerized diagnostic test to find out. See, your car comes equipped with a system of microprocessors constantly monitoring each component of your car for any changes or problems.

Once one of these sensors notices a problem, they’ll send your car’s main computer a ”fault code” indicating what’s wrong. Your computer (either the PCM or ECM) will save the code and the check engine light will turn on.

When your check engine light—sometimes called a service engine soon light—comes on, you have two options: take it to a mechanic for a diagnosis, or do it yourself.

When your Check Engine Light comes on, Telle Tire & Auto Centers can help. For 82 years and four generations, the Telle family has understood the importance of providing strong value through quality products and services. Our ASE-certified technicians provide trusted excellence built on generations of long-term relationships and proven excellence.

See what our past clients have to say, or come in and see for yourself. From basic maintenance to comprehensive diagnostics and full engine repair, Telle Tire & Auto Centers are your one-stop-shop with you every mile of the way.

Wait, I can diagnose the car problem myself?

Well, maybe. You can use a specialized reader—perhaps the OBD-II—to identify the fault code. Basically, the reader will tell you some basic information and identify the system having the issue.

For example: maybe the fault code came from your oxygen sensor. Great. So now all you have to do is replace your oxygen sensor, right?

Not so quick. Just because the fault code stems from your oxygen sensor doesn’t mean that the problem is with your oxygen sensor. All it means is that the oxygen levels are off. There are ten different things that could cause a fuel-oxygen imbalance. Maybe there’s a vacuum leak. Maybe there’s a fuel injector problem. You could replace your oxygen sensor all day, but if the underlying problem is a vacuum leak, you’re wasting your money.

Just because it’s easy to use a reader to identify the fault code doesn’t mean you should. In fact, the rise of computerized car systems has made it easier than ever for inexperienced mechanics and DIY-ers to misdiagnose car problems.

So, when your check engine light turns on, don’t waste your time and money. Turn to an experienced mechanic for help.

We can help you determine why your check engine light is on

At Telle Tire & Auto Centers, we use the latest equipment in computer diagnostic tests, and the resulting fault codes as a compass rather than a direct answer.

Once we know the general problem area, we’ll examine your car. We’ll research every possible solution based on its make, model and year. We’ll troubleshoot. We’ll figure out what, exactly, is the root of your car problems. Then we’ll consult with you and provide you with the best, most cost-effective solution.

Why do we go the extra mile? Because we value our relationship with you. Maybe that’s why St. Louis has trusted us with their car repairs since 1942.

So, when your check engine light comes on, bring your car in. We take the worry out of car service.

Trust your car with the automotive repair technicians that go the extra mile.