Check Engine Soon Light

It might present itself as a “Check Engine”, “Check Power Train”, “Service Engine Soon”, or just a little engine symbol – but whichever way your car presents the check engine light, it is important not to ignore it.  If a check engine light is ignored for a long period of time, there could be extensive damage done to your car.

Why Was the Check Engine Soon Light Invented?

The check engine soon light is part of your vehicle’s emissions system and it was designed to alert you about emissions problems monitored by the car’s computer.  It became standard on cars in the 1980’s.  Federal law actually mandates that all new cars sold in the United States have a check engine light.  In addition to turning on the check engine light in your car, the car’s computer also stores a code that identifies the source of the problem that allows the problem to later be identified by one of our technicians using a scanner.  This same computer also controls and monitors vehicle performance, fuel mixture, ignition timing, regulates engine speed (RPM), and in some cars it even tells the automatic transmission when to shift.  

What Causes the Check Engine Light to Come On?

There are some common things that cause your check engine soon to come on.  These things include a loose gas cap, faulty oxygen sensor, bad battery, alternator, baseline parts, and hose & wires.  Sometimes the cause of a check engine soon light is as simple as a gas cap that has not been properly secured. In this case, it is a simple fix to make the check engine soon light turn off.  A second cause might be a faulty oxygen sensor.  While a faulty oxygen sensor may be over diagnosed, it is still a common cause of the check engine soon light coming on in your car.  The main purpose of an oxygen sensor is to examine the amount of oxygen in your car’s exhaust system as compared to the oxygen outside of the system.   The third possible cause of the check engine soon light coming on is a bad car battery.  Our technicians can use an automotive computer to make sure that your battery isn’t causing problems with your car’s electrical system and electronic parts.   A forth cause of the check engine soon light coming on might be your car’s alternator.  Our technicians can test your alternator and diodes.   Your car’s alternator converts alternating current (AC) to direct current (DC) though a series of diodes.  If these diodes fail to complete the conversion, then the AC current can pass into your car’s electrical system confusing your car’s computer and turning on the car’s check engine soon light.  The fifth possible cause of your check engine soon light coming on can be your car’s hoses and wires.  Thus, it is important to get your car’s hoses and wires inspected by our technicians.  If a bad battery and alternator are ruled out as the cause for your check engine light coming on, our technicians may do a visual inspection of your hoses and wires.  During a visual inspection we look for oil soaked wires and vacuum hoses.  We also keep an eye out for frayed wire and anything else that looks out of the ordinary.  Lastly, our technicians may check that your car’s baseline parts are properly controlling fuel delivery and producing high voltage to fire up your car’s spark plugs.