KW590 is a great upgrade from the more basic auto code scanner tool. The major function is working on vehicle engine system. Once plugged into your vehicle's 16pin OBDII DLC after starting the ignition, you can choose to diagnostic what you want to know about your cars engine system, oxygen senor, evaporative control system, etc. Then find out the problems and perhaps fix it. Works on all 1996 and later OBDII compliant US, European and Asian vehicles Easily determines the cause of the Check Engine Light ( MIL) Retrieves generic (P0, P2, P3, and U0) and manufacturer specific (P1, P3, and U1) codes Turns off Check Engine Light (MIL), clears codes and resets monitors Displays DTC definitions on unit screen Views freeze frame data Displays monitor and I/M readiness status (emissions) Identifies pending codes Eads live PCM datastream Displays live O2 sensor test data Graphs data C (1996 and newer) Reads, stores & playbacks live sensor data Memory/battery backup for off-vehicle data review and analysis Support six languages: English, French, German, Dutch, Spanish, Russian Performs modules present test Retrieves vehicle information (VIN, CIN and CVN) Supports CAN (Controller Area Network) and all other current OBD-II protocols Built-in OBD-II DTC lookup library Large easy-to-read backlit LCD screen Software upgradeable via internet Prints data via PC