What to Do When the Check Engine Light Comes On

| October 13, 2012

engine light onThe Check Engine light can help you avoid some expensive auto repair bills. The key is to visit a vehicle repair shop as soon as possible to have it checked out. Find one near you in the DexKnows auto repair listings. So here’s what that light might mean, and what you should do when it comes on.

What is it telling you?

The Check Engine light is telling you that the car’s computer has detected a problem. The good news is that most problems are relatively minor, but that’s not a reason to ignore it. Your car has a host of sensors that monitor how the engine is running. The primary reason for the sensors is to control the exhaust emissions and let you know when there’s a problem.

Two of the most common reasons for the light to come on are a loose gas cap and a faulty oxygen sensor, sometimes called an O2 sensor. The gas cap is an easy fix: just see if it needs tightening. If it did, wait a couple of days to see if the light goes out. But if the cap was secure, there’s another reason for the light to come on, and you need to know what it is.

Get the code read

Somewhere under the dashboard is an electrical connector. A vehicle repair shop can plug a code-reader device into this, and the car’s computer will send it a fault code. (This is what’s called the onboard diagnostics, or OBD, system.) The technician can then look up the code to determine the fault.

Oxygen sensors monitor what goes out your car’s exhaust. If the car starts running too rich or too lean, the light goes on. Unfortunately, O2 sensors have a somewhat limited life, so more often than not, an O2 sensor code means the sensor has gone bad. These aren’t particularly expensive to replace, but because they’re buried underneath the car, it’s not really a job for the amateur.

If the light is flashing

A Check Engine light that’s flashing is really trying to get your attention — and for good reason. When the light flashes it means the computer has detected a condition that’s going to lead to serious engine damage and large repair bills. This can be caused by something as simple as a misfire.

If you get to the auto repair shop quickly, they can make the necessary repairs, and it probably won’t cost that much. It’s certainly less expensive than a new engine or catalyst!

The Check Engine light is there for a reason, so don’t ignore it. When it comes on, check the obvious. But if that doesn’t cause the light to turn off, you’ll need to get a proper diagnosis. Use the DexKnows auto repair listings to find a local repair shop. Have them read the code and find out what’s wrong. Remember: If the Check Engine light is flashing, you need to get there straightaway.

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Category: Auto Repair, Autos

About the Author ()

After twenty years in the automobile industry the craft of wordsmith called. Putting down the wrench, Nigel picked up a keyboard on which to express his passion for all things automotive.