Buying a scan tool is easy, but figuring out which scan tool is the best one for you takes some research. You want a scan tool that will work on your vehicle (or the vehicles you service most often if your are a professional technician), is user friendly (easy to use menus) and can be upgraded. The tool also has to fit your budget. You cannot always get everything you want in a single scan tool. Some tools have more features than others. Some are slim, hand-held models and others are more bulky. Some can perform a wide range of tasks, while others can do only a few limited functions. Some require a major investment while others are relatively cheap. Finding the scan tool that is right for you is not easy because there are so many different ones from which to choose. There are basic code readers, older pre-OBD II scan tools and current OBD II-compliant scan tools. There are OEM scan tools and aftermarket scan tools. There are dedicated scan tools and software for converting laptop PCs, tablets and smart phones into code readers and scan tools. How do you choose from such an array of products? FACTORY OR AFTERMARKET SCAN TOOL? If you are a professional technician and specialize in a single import nameplate, for example, the OEM factory scan tool probably will be your best choice. Factory scan tools generally provide access to all the diagnostic trouble codes (both "generic OBD II" and "enhanced"), all the on-board test procedures, and usually most of the on-board electronics beyond engine performance and emissions (such as ABS, air bag, suspension and so on, if these systems have scan tool diagnostics). Unfortunately, OEM factory scan tools also are the most expensive and least flexible way to go. To make matters worse, some factory scan tools are essentially "dealer only" tools. The version they sell to the aftermarket may not be a full-featured unit and may lack some of the diagnostic tests or other capabilities that are included in the tool used by the new car dealer technicians. Some may not display all of the same PIDs (parameter identification) or data lines as the dealer tool. Others may do only engine performance and emissions, but not ABS, air bags or anything else. This situation is gradually improving as time goes on. For Honda and Accura applications, Teradyne (now out of business) made a Pocket PC platform that used the SAME software as the OEM Honda scan tool. For repair shops that specialize in a broader mix of import and/or domestic nameplates, buying a different OEM factory scan tool for each may be more than they can afford. Most factory scan tools sell in the $2,000-plus range, and they work on only a limited range of vehicle applications. Some OEMs have one scan tool for pre-OBD II vehicles and another for the newer OBD II-compliant vehicles. For this kind of situation, an aftermarket scan tool such as those made by Actron, AutoXray, Equus, OTC, Snap-On and others might be a more affordable repair solution. But what kind of aftermarket scan tool? Aftermarket scan tools run the gamut from those for specific import makes (such as Volkswagen, Mercedes-Benz, etc.), to those that can interface with nearly all makes and models, both import and domestic. The "universal" scanners provide the most flexibility, but typically require purchasing additional cartridges and adapters to handle Asian and European makes. When you add up the cost of the scanner itself ($1500 to $5,000 or more for a professional grade tool), plus the different cartridges and adapters, which may range in price from $300 to $800 or more, plus annual licensing fees, you can make a significant investment in diagnostic hardware and software, which also will have to be periodically updated with new software and/or hardware to keep up with changing technology. Keep in mind that every aftermarket scan tool is different. An $800 scanner will not have the same features and capabilities as one that costs five times as much. In some cases, you are paying extra for color graphics, a larger display or more built-in features, rather than add-ons, etc. So you have to shop and compare carefully to see exactly what you are getting. WHICH SCAN TOOL PLATFORM IS BEST? In recent years, various vendors have developed software and apps that allow your desktop PC, laptop PC, tablet or smart phone to function as a plug-in or wireless scan tool. The sophistication of the software varies greatly as does its usefulness as a diagnostic tool. The simplest and cheapest packages give you the ability to use your computer or mobile device to communicate with the OBD II diagnostic connector on a 1996 or newer vehicles and use it as a code reader to display and clear generic OBD II fault codes. The better packages include enhanced codes for specific vehicle applications, and also may include the ability to display various PIDs such as sensor voltages, switch status and so on. The best software also includes graphics for displaying sensor voltages and other data. Some scan tool software and apps require an interface cable or wireless connection to link your computer or device to the vehicle. In some cases, the software supplier provides the software at no charge but requires you to purchase the cable. The software, by itself, is useless without the cable or wireless connector to link the tool to your car. If you are resourceful and want to save a few bucks, there are numerous sources on the Internet where you can buy interface cables separately, or kits or plans to build your own cables. Software is available that can convert a laptop or any other Windows-based PC into a scanner. Most require a Windows XP or higher operating system. Like the hand-held devices and smart phones, a laptop or PC also requires an interface cable or wireless connector to link your computer to your vehicle. One of the advantages of using a laptop or desktop PC as a scanner is the larger screen display. This makes it easier to read and list more information on a single screen. Most laptops have a screen that measures 12 to 17 inches diagonally, while most PC monitors range in size from 14 to 24 inches or larger. Another advantage of using a hand held device, smart phone, laptop or desktop PC as a scan tool is that it can easily be updated by downloading the latest software from the Internet. This also can be done with most dedicated scan tools using your PC for the download, and a USB cable or flash drive to transfer the update to the tool. On the other hand, dedicated scan tools are designed to be scanners and nothing else. You cannot surf the Internet with them or check your e-mail or auctions on eBay. But you can fix cars with them. Many professional-grade scan tools also include additional hardware circuitry and test leads that allow you to use the same tool as a multimeter to measure voltages, resistance and current. This is an extremely useful feature to have and eliminates the need for yet another piece of test equipment. Some of the more expensive scan tools also have the added ability to function as graphing multimeters or digital storage oscilloscopes. Being able to display sensor voltages as waveforms makes it much easier to detect problems that are nearly impossible to diagnose any other way. If you are looking for a multi-purpose tool that can be used as a scanner, multimeter and scope, choose one that can display more than one waveform at a time. Several units that are now on the market can simultaneously graph and display up to four different PIDs. DOES YOUR SCAN TOOL COVER YOUR VEHICLE? With import vehicles, coverage continues to be a major issue for some European makes. Until the arrival of OBD II, many imports lacked the ability to display sensor data or other diagnostic information through a scan tool. Many of the pre-OBD II Asian imports provide fault codes at the ECM with LEDs or have other flash codes so you do not need a scan tool for diagnostics. But on 1996 and newer vehicles, a scan tool has become mandatory. Some aftermarket universal scan tools and software packages provide good coverage on domestic and Asian makes, but only limited coverage on European makes. Others only read "generic" OBD II information on 1996 and newer import makes. One of the things to check out, therefore, when shopping for an aftermarket scan tool or scan tool software package is a list of what is covered, and what is not (which is much harder to obtain). Some claims can be misleading. A vendor may say their product or software package covers a long list of makes and models, but it may be only generic OBD II information. They may not even have enhanced codes for the applications listed. Others may provide all the OBD II codes but no additional codes for ABS, air bags or other systems beyond the engine and powertrain. Some may have limited diagnostics and not include all the factory tests or procedures. If you are not sure exactly what is or is not included, ask before you buy. DO YOU NEED MORE THAN ONE SCAN TOOL? Since it is obvious that one tool cannot do it all, many technicians buy more than one scanner and use different tools for different purposes. An inexpensive code reader can be used to read and clear most OBD II codes on 1996 and newer vehicles. This type of tool often can be used to make a quick diagnosis and, in many cases, you may not need anything else. But for advanced diagnostics, no-code fault diagnosis or any procedure that requires bi-directional communication with the vehicle computer, you need a professional grade scan tool or software package with advanced capabilities. One of the best software packages that is currently available checks all the sensor circuits and compares the values to known-good values to flag potential problems. For some jobs, you also may need a tool that can graph or display waveforms. That means buying a digital storage oscilloscope if you do not buy a high-end scanner that can do both. Most scan tools display data stream values, which is what …

Fonte: AA1Car.com