Many of us have had our check engine light come on.
Depending on your personality, your reaction may have been anything from total panic to completely ignoring it. Let’s review some information that will help you know what to do.
The Check Engine or Service Engine light is a warning light, which is warning you that something is wrong. That something could be as simple as a loose gas cap or as important as a condition that may cause expensive damage. When the light comes on, it may burn steadily or it might flash. A flashing check engine light means that there is something wrong that could lead to severe damage. When that happens, you want to have the car checked by your service center as soon as you can. While it is flashing, it is not recommend that you not tow a trailer, haul heavy loads or drive at highway speeds. That kind of driving could lead to damage before you can get in to get your vehicle fixed. A steady check engine light is not as urgent. You still want to get your car in for a diagnostic inspection, but you can work it into your schedule.
The first thing to do when you have a steady check engine light is to check the gas cap. If it is not on tight, twist it until it clicks three times. If a loose gas cap triggered the check engine light, it will reset after several trips. It may take a few days before the light cycles back off. If the light persists, your car needs to be checked out.
Every modern car has an engine control computer that runs most of the engine functions. When a sensor reads that something is out of whack, the computer will first try to compensate for the problem. If it can’t, it turns on the check engine light and stores a trouble code in the computer’s memory. When you go into your service center, the technician will attach a scanner to a data port and read the stored trouble codes. The codes tell the technician what parameters are out of standard so he knows where to start looking for the problem.
It is important to know that the trouble codes do not pin point the exact cause of the problem. They just give the technician a starting point for diagnosis. Any number of problems could cause a given trouble code. The technician will further inspect the vehicle and perform other tests as needed to determine exactly what needs to be done to repair your vehicle. He’ll reset the check engine light and you’re good to go.
Now don’t listen to the amateur advice you’ll find on the internet about how to deal with your check engine light. Some say you can disconnect your battery so that the light goes off. There are several problems with that. The obvious problem is that you’ve done nothing to fix the car; you have only turned off the light. The other problem is that you can actually erase some of your control computers’ learned memory. If that memory is gone, your vehicle needs to relearn and make adjustments for your engine, driving conditions and driving habits. Don’t disconnect your battery to deal with a check Engine light.
Unless you’re a skilled automotive diagnostician, avoid buying a cheap consumer scanner or getting your codes read at an auto parts store. Knowing the code is only a starting point to diagnosing the problem. You need a trained technician equipped with the latest high-tech diagnostic equipment to get you back on the road safely and avoid expensive repairs later on.