Yext Auto Repair Article

12.01.08

Diagnosing a Check Engine Light

One of the most elusive diagnostic tools that your engine is equipped with is the “check engine light.” For many, this light is a pestering reminder that they need to get their car checked. Ironically, for many professional auto mechanics, the check engine light is equally frustrating. The reason is that the engine is designed to light up when even the slightest malfunction occurs with the engine; while this is a good thing because it ensures that a potentially serious problem does not go undetected, in many cases the warning light is unwarranted and the problem is not urgent. But the tricky part is: it’s hard to tell unless you get it checked out.

Light Malfunction
Sometimes the check engine light malfunctions on its own. In this case the light needs to be reset. The best way to make sure that this is the case is to purchase a scan tool that will allow you to read the diagnostic code that your car displays that corresponds with the error it’s detecting. These automotive scan tools can be purchased at most auto repair shops and auto parts stores; they attach to the diagnostic connector that is located at the front of the vehicle usually around the steering wheel. The diagnostic connector is usually hidden underneath the hard plastic paneling surrounding the area around the steering wheel. After the scan tool is connected and the car’s ignition is turned on, the diagnostic tool will display a code that corresponds with the fault code registered by your car’s on-board computer. This code is known as the diagnostic trouble code (DTC). If the idea of removing the paneling and exposing the internal wiring of your vehicle sounds too complicated to you, you can always take your car to the auto shop.

The Value of a Diagnostic Trouble Code
With your diagnostic scanner in hand, you can record the diagnostic trouble code recorded by your vehicle’s on-board computer memory. This code is a very useful diagnostic tool that allows the mechanic to isolate the problem and save time in diagnosing among the many potential problems. While this code allows an expert to isolate the region in which the problem occurred, there is no way to know exactly which part needs fixing or replacing. This is why, in cases where the check engine light is not the result of malfunction, you will still have to take your car to a professional. However, this procedure is still time saved and time saved is money saved; with labor cost as expensive as they are, self-diagnosing your car’s problems is a good, economically sensible alternative.

Drawbacks and Benefits of Self-diagnosis
The drawback of self-diagnosis is that you have to purchase a scan tool which can cost over a hundred dollars and you have to look through the corresponding codes to identify the error reported by the diagnostic tool. Some larger auto repair shops may offer a free diagnostic check and scan, which may be a cheaper alternative to self diagnosis. However, the price saved may be added onto the cost of servicing and repair.

In general it’s a good idea to diagnose your own check light engine problems yourself as this can prevent an unnecessary trip to the repair shop. Knowing the list of possible complications that correspond with the error code recorded can also help prevent you getting ripped off by an auto repairman looking to make an extra buck off an ignorant driver. For more details on the meaning of specific error codes, check your car’s maker as these codes often vary from manufacturer to manufacturer.