Diagnostic scanner is a useful equipment for your home garage or workshop. With the help of these scan tools you will be able to know the condition of various systems of a car. These gadgets are able to read the error codes sent by various systems in a car. Once you are aware of the problem you can start diagnosing it. Some of these diagnostic scan tools can even send coded messages to car systems. A good professional scanner should comprise of basic, advanced, and special features. It should also offer extensive vehicle coverage and be internet updateable in order to diagnose the most recent fixes.