How to Buy Diagnostic Tools for Your Vehicle

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How to Buy Diagnostic Tools for Your Vehicle
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How to Buy Diagnostic Tools for Your Vehicle

Many different options of diagnostic tools for vehicles exist. These may include tire gauges, battery sensors, and a variety of other tools specialised for one component of the vehicle. However, many vehicles manufactured after the mid-1990s have a standardised diagnostic tool. The downside is that the diagnostic scan tool can have a large upfront cost, but the positive aspect is that it truly is the only diagnostic tool a vehicle owner needs and affordable models can be found. Further, certain scanners are better suited to certain vehicles, so prospective buyers should carefully review the device's capabilities before purchasing.

As automobile technology has improved, so too has the system for repairing vehicles. Many newer vehicles integrate computers into their operation that can run components like the engine, transmission, and ignition. While these computers are disfavoured by automobile traditionalists, they do make it simple and straightforward to diagnose issues with the vehicle. The scan tool allows the user to connect to the car computer which is constantly gathering data from all of the vehicle's systems. This allows the car computer to not only optimise performance, but also relay information about problematic components or systems.

The Vehicular Computer Interface

The standard operating system for vehicles beyond the mid-1990s is known as On-Board Diagnostics II. When people typically think of a vehicular computer, they often associate it with taking in real-time information from sensors around the vehicle and optimising performance of the different components it controls. For example, to start a vehicle, many systems need to respond simultaneously. The vehicular computer sends out the signal to all the relevant parts. In addition, while the vehicle is in motion, the vehicular computer is fine-tuning a variety of things to maximise performance such as fuel injection, engine rpm, temperature, etc.

In addition to maximising performance, the vehicular computer can also provide a wealth of knowledge about the inner working of the vehicle. Since the computer is constantly collecting data in real time, it can also alert the owner or operator to anything that seems out of the ordinary. When one of the sensors is sending data to the vehicle computer that does not compute, the computer triggers one of the warning lights in the vehicle such as "check engine". Prior to the vehicular computer, the vehicle had to be examined by a professional who could use deductive reasoning and process of elimination to determine the problem.

The Diagnosis

The vehicular computer does not stop functioning when there is a problem. It simply does the best it can with the data it is being provided which is generally sufficient to get the driver to their destination, unless something is really wrong. When the vehicular computer senses trouble, it stores a code that relates to the issue. Scan tools can be plugged into the vehicular computer and report the diagnostic code. While these diagnostic codes may not always be perfectly exact, they eliminate much of the guess work involved in diagnosing these issues before vehicular computers were standard equipment.

In the earlier years of vehicular computers, scan tools were prohibitively expensive for ordinary car owners and were only used by professional technicians. To make matters more complex, the scan tools from one manufacturer were not compatible with vehicles from another manufacturer. Scan tools can be highly advanced or simple machines that are limited to simply reporting the problem code.

Scan Tool Codes

Once the scan tool is plugged into the car computer, usually through some easily accessible port on the dashboard, the tool can reveal the trouble codes. Some more advanced scan tools can explain the code right on the screen. Others come with additional literature to reference. Some scan tools direct the user to websites or other databases where the code can be entered to determine what the code relates to. Scan tool codes are not only important for vehicular maintenance, but they also may impact vehicle inspections if the emissions or other vehicular components are not functioning properly.

Scan Tool Data

For straightforward vehicular issues, a basic scan tool that only reads codes may suffice. However, performance enthusiasts as well as technicians often prefer the advanced functionality of higher end scan tools. These scan tools allow the user to review the hard data collected by the vehicular computer. A trained eye can review this data and notice patterns, fluctuations, and other readings out of the ordinary that could indicate problem areas or areas that could be tuned for better performance.

Some scan tools can be connected to an actual computer. This usually means additional cost, but allows the user to create spreadsheets and printouts. This may be advantageous to some, especially to professionals and technicians who wish to show the data to customers. It also allows the user to use computer software to detect patterns and issues with the data. Sometimes, variations in the data are too subtle to be caught by the naked eye but high powered computers can provide clarity.

Types of Scan Tools

Scan tools come in many different varieties. Shoppers should carefully evaluate which type best suits their needs. Users who do not need high-end functionality may simply require a basic hand-held model. Users who are focused on greater vehicular performance or automotive professionals should consider more advanced models.

Hand-Held Scan Tools

Hand-held scan tools are generally simple, straightforward, and rugged. These are the choice of most consumers, as they are relatively inexpensive and easy to use. They are also flexible and can be used with many different types of vehicles from various manufacturers. There are base models of hand-held scan tools as well as more sophisticated models. These additional features include more advanced diagnostics, real time monitoring, and control over other parts of the vehicle.

Mobile Based Scan Tools

Many mobile based applications can function as a scan tool. Bluetooth or USB adapters can be plugged into the vehicular computer access point. This allows the user to connect their mobile device to the vehicle computer. Certain applications provide many of the same features a scan tool can provide. While mobile-based scan tools are typically not as complete or reliable as dedicated tools, they do offer a cost-effective option for users seeking just basic functionality.

PC-Based Scan Tools

PC-based scan tools do not relay data to the user directly. Instead, the data and signals they detect must be translated through a computer. PC software can decode the data onto the computer monitor. This allows for more advanced functionality by using the PC software to display and organise the data, detect additional patterns, and provide additional storage for increased amounts of data. They can also combine the use of different software programmes to get more accurate and precise results.

Data Loggers

The final type of scan tool is known as a data logger. Data loggers record real time data as the vehicle is in use and either remotely transmits the data or stores the data for later use. These are often utilised by insurance companies to more accurately record the driving habits of their customers. It can also be used by drivers who are not well-versed in vehicular maintenance, because it can be brought to a professional for their own expert review.

How to Buy a Diagnostic Tool For Your Vehicle on eBay

eBay has a wide variety of scan tools available ranging from the most simple to extremely advanced. A basic keyword search is an ideal starting point. Using the search box on every eBay page, shoppers can type in keywords such as "scan tool" or "vehicle diagnostic tool". Specific words can be added to the search such as "hand-held" or "PC-based". This provides you with a more narrow range of results so that you are able to find the correct diagnostic tool more quickly for your vehicle.

Once shoppers have determined what kind of product is best suited to them and what their budget constraints are, they can begin to refine their search. Prospective buyers can then narrow the results by selecting the type of diagnostic tool they desire and any features that they want. Finally, shoppers can sort the results by relevant factors such as price, buying format, and time left at auction. Regardless of what the shopper is seeking, eBay is sure to provide the widest range of options so that any buyers needs can be met for the right price.


Scan tools provide the vehicle owner or technician access to information related to the vehicle's various systems. It can provide data that may indicate problematic areas or areas that could be more finely tuned to increase performance. They provide codes which can then either be deciphered by the user or connected to a computer for additional processing. Shoppers should be sure to carefully consider which type of scan tool best meets their needs.

Hand-held scan tools are the most popular choice among consumers looking for an inexpensive base model. They can typically provide sufficient information to the consumer to determine if a professional needs to be consulted and what the issue may be. More sophisticated models can be more pricey but offer advanced functionality such as PC compatibility. Prospective buyers should also consider mobile solutions, which can be connected to the vehicle computer via Bluetooth or USB. eBay is sure to provide all shoppers with the best diagnostic tool for their vehicle.

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