You may have heard people say that “computers are all around us.” Hopefully you’re not too paranoid about that, especially since it is true to a certain extent. For example, you probably drove to work today with the assistance of a little “computer” inside your engine. Today’s Technology Tip is about the little computer in your car that keeps it running. More importantly it's about how to handle those annoying “Check Engine Soon” lights on your dash board.
Depending on the age, make and model of your vehicle you probably have more than one computer in it
Controlling the engine is the ECU, which stands for Engine Control Unit. This one is usually the most expensive one to replace and it is designed to control the engine so you can get optimum performance and efficiency out of it. Generally speaking, the newer your car the more complex the ECU is. Compared to your desktop computer however it’s pretty primitive. For example, your car’s ECU probably has less than 1 MB of memory compared to the several Gigabytes most new desktop computers come with. But that’s enough to run your engine efficiently since the software is so much simpler. For more information about your car’s computer check out this site: http://auto.howstuffworks.com/car-computer1.htm
For most of us, the most annoying thing your car’s computer ever does is light up that “Check Engine Soon” light on the dashboard. The ECU in your car includes software called OBD which stands for On Board Diagnostics. This software constantly monitors your engine for trouble signs or inefficiencies. When sensors detect problems the “Check Engine Light” appears on your dashboard. Because engines that run inefficiently pollute more, OBD software was mandated on all cars built from 1987 on. Just for reference the original OBD software was upgraded in 1996 and is now calledOBD II. For more information about OBD software check out this link: http://www.asashop.org/autoinc/may2004/mech.cfm
Now for the really important question, how do you get the “Check Engine Light” off? The light might turn on for any or a number of reasons. Even though the technology is there for your new car to verbally tell you what’s bothering it, you still probably have to take it to a dealership or mechanic so they can plug it into a special OBD reader and check what “error code” is causing the light to come on. This “diagnostic test” usually costs $50-$100 and is about as complicated a task as making toast. But since you don’t have the equipment at home, and your car won’t just tell you what’s wrong with it, you’re stuck paying for the diagnostic.
Well actually here’s another option. Many autoparts stores have the OBD readers on site and they will do the diagnostic test for you for free (AutoZone is one such store for example). They can’t clear the code (get the light to turn off) but they can tell you what the problem is (in hopes you’ll buy a replacement part from them).