My “Check Engine” light is on.  What do I do?  Most people are uncertain what to do when that little red light comes on.  How serious is it?  Should I immediately pull over to the side of the road and shut off the engine, or, can I ignore it and drive another 20,000 miles?

The good news is that there is rarely any serious damage potential when the “Check Engine” light comes on.  This light is the alarm bell for your car’s complex computer control system.  Your car has over 50 sensors, and monitors hundreds more system performance indicators for the ignition system, fuel system, cooling system, and other systems.  The computer has allowable limits for all of these readings.  When a reading exceeds the limit, the light comes on.  The vehicle will be either outside of optimum emissions performance, have deteriorated fuel economy, or even may perform poorly.

Let us stop here to tell you what the really serious lights are.  These are your oil pressure light and your engine temperature light.  If either of these lights come on you should find the first SAFE place to pull off of the road and then shut off the engine.  Call your repair shop and have the vehicle towed in.  Even a few minutes of operation with either the oil pressure light or engine temperature light illuminated can result in a repair bill beginning at $600 and easily going to several thousand dollars.

A new Georgia state law prevents you from getting an emission inspection if your check engine light is on.  You will need to have your car serviced before the state inspection can even be performed.  This requires connecting a diagnostic computer to read the trouble code and then diagnosing what caused the problem.  There is always a charge for connecting the diagnostic computer.  In most shops in this area the charge ranges between $59 and $89.  This also includes 30-45 minutes of technician time for diagnosis.  The most typical cause of the problem is over due maintenance.  It can be a very dirty air filter, old and defective spark plug wires, defective EGR or PCV valves, a build up in the fuel induction system, or just a faulty sensor.  These items are usually correctable for under $200.  The good news is that it is much less frequent that the car requires a new computer module.  Replacing a computer module usually costs $500 or more.

Do you have a question about your car?  Send it in to ….

By Brian Klaubert & Brian Warbington of Christian Bros. Auto – Hamilton Mill, Dacula.