Last updated: August 2023

What to Do When Your Check Engine Light Comes On

You glance at your dashboard as you pull out of the driveway or away from the pump, and then you see it: that ominous, glowing CHECK ENGINE light. Your first feeling might be one of dread. Is this going to cost me a hefty chunk of change? Don’t panic! We’ll walk you through a few things you should do when your dash tells you it’s time for a checkup on your engine.

What makes the check engine light come on?

The common name for this light is a little misleading, since the check engine light can be activated by a number of issues, not just a problem with the engine. In fact, this light is also called the malfunction indicator light (MIL). The light is activated when a car’s on-board diagnostics (OBD) system detects a problem with the performance of some of the car’s major components. According to Consumer Reports, the OBD will look for different things depending on the make, model, and year of a car.

The folks at AutoZone list the top 5 reasons a check engine light might activate. You could need to:

  1. Fix a loose, damaged, or missing gas cap.
  2. Replace your oxygen sensor.
  3. Replace your catalytic converter.
  4. Replace your massive airflow sensor (MAF).
  5. Replace your spark plugs or plug wires.

So, how do you figure out what the real problem is?

What do I do when my check engine light is on?

First, check your owner’s manual to see what your car manufacturer recommends.  While you shouldn’t panic about a lit MIL, you shouldn’t ignore it either. Leaving an engine issue unaddressed could lead to even more expensive repairs, so it’s best to find out what the problem is ASAP. After all, you don’t want to be stranded on the side of the road with a broken down car (though if this happens, your roadside assistance plan could help).

So what do you need to do? According to Consumer Reports, when the MIL is activated, the car’s computer memory stores a “trouble code” specifying the problem. By translating this trouble code, you or your mechanic can pinpoint the problem and make the necessary repairs. To do this, auto repair shops use an electronic scan tool or diagnostic computer to read this code, but there are also some relatively inexpensive code readers out there for those who want to take the DIY approach. Once you know the code and what the code indicates, you can pinpoint the issue and work to address it directly. Taking care of little problems early on is one of the five most inexpensive ways you can help make your car last longer.

Tip: If you bring your car into the folks at Pep Boys, they will do a free code retrieval by scanning the computer board of your car, documenting the diagnostic trouble code, and providing you with a repair estimate. Other auto supply stores in your area may offer a similar service.

At Direct Auto, we’ve got you covered from car insurance to car maintenance tips. Visit our Learning Center for more helpful information that’ll keep you driving.

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