Question:

My check engine light is on and my boyfriend thinks he can get the code read and know what part to replace to fix my car.  I say it’s not that simple.  Who’s right?

Answer:

Good news – you are!  Just look at it logically: there are hundreds of things that can go wrong with your vehicle.  Some are simple and some are quite complicated.

Let’s take a step back.  Over 80% of engine functions are computer controlled.  The computer receives information from dozens of sensors.  When a sensor reading is out of range, a trouble code is entered into the computer and the Check Engine Light is illuminated.

It’s a common misconception that the trouble code will tell you exactly what is wrong.  For any given trouble code, there is any number of faults that would trigger the code.  For example, a code indicating a misfire on cylinder three could be due to a bad spark plug, a failed coil, ignition problems, compression issues, etc.  Each of those possibilities requires additional diagnosis to confirm or rule out a cause.  Once a trained technician with state-of-the-art diagnostic tools and extensive research databases can nail down the problem, then he can set about getting it fixed.

A complicated diagnosis may take some time.  Your boyfriend might be tempted to bypass a diagnosis charge by taking a trouble code reading with an inexpensive scan tool and start replacing parts.  He might get lucky, but chances are you’ll end up spending more time and money than if you went to a professional with the right equipment.

A final word – a flashing Check Engine Light indicates that a condition exists that could lead to serious damage.  You should get to your service center right away.  A steadily illuminated Check Engine Light is less urgent so you can get it checked at your convenience.  But keep in mind that a minor issue today can become more serious if left unresolved.