OBD Scan Tools
Have you ever visited your mechanic and heard them say that they will "scan" your car or truck? Or have you ever later looked at your mechanic's bill and saw some kind of charge for "diagnostics"? What does that mean? It sounds like something out of Star Trek, doesn't it? Well, mechanics these days, unlike their counterparts long ago who had to simply fix cars by either doing an eyeball inspection or tearing them apart and putting them back together again, have a new tool that can help them immensely when it comes to fixing a problem with your car, truck or other vehicle. Instead of having to pull a car's parts apart looking for the problem, they can now often diagnose the problem after running your car's on-board diagnostic tools (otherwise known as OBD scan tools.)
"OBD scan tool" is a generic term that does not refer to any specific type or brand of scan tools. In an automotive context, the generic term OBD scan tools refers to a car's own on board diagnostic system. These on board diagnostic systems were designed by the manufacturer with each specific care model in mind in order to effectively let the car diagnose its own problems. But, of course, you can't generally use your car's OBD scan tools at home. Mechanics these days are equipped with the technology that allows them to access your car's OBD scan tools and find out, often within a matter of minutes, what exactly is causing that clanking sound or that funny read out on your car's dashboard display. To put it more technically, your OBD scan tools allow your automotive mechanic to access health information for most of your vehicle's various sub systems.
OBD scan tools were introduced at the same time as on board computers – in the early 1980's. This was about the time that computers were becoming more than just the domain of the government or highly technical "computer geeks" and actually becoming common and useful in day to day society. Ever since the first on board computers (and thus the first OBD scan tools) appeared on the scene, the amount of diagnostics they could actually perform has varied a great deal.
Early OBD scan tools would just light up an indicator light if a problem was detected. The check engine light and low fuel indicator are both the result of OBD scan tools detecting a problem with one of your vehicle's on board systems. These lights (i.e. the check engine light, et al) are called "malfunction indicator lights" (or MIL's for short) and are some of the first rudimentary ways that your car could actually tell you that something was wrong with it. Unfortunately, while the MIL function of OBD scan tools was helpful, it could do no more than point your mechanic to the general vicinity of what was wrong. How many of you remember that "check engine" could have meant about 500 different things? The mechanic was often scratching his head just as much as you were after that light came on.
Nowadays, modem powered OBD scan tools use a standardized form of communication to provide real time data when it comes to a car's malfunctioning part or system. These come in the form of "diagnostic trouble codes" (or DTC's), which a mechanic can easily read (or, more likely, look up) and then point to the exact problem with the vehicle. This use of OBD scan tools has simplified the problem of getting a trouble-prone car fixed and allowed mechanics to go about their work with much more efficiency and ease.