Check the listing for details. OBD Code Reader Automotive OBD2 Scanner Car Check Engine Fault Diagnostic Tool. Condition: New. Listed at 13.01 USD. Read Code and Clear Code: Knowing the code will prepare you for a cost estimate of the repair at the repair shop, so you can save money in diagnostics, You can use the MS309 to retrieve generic codes, manufacturer specific codes and pending codes in seconds with DTC definitions displayed under codes, quickly locate problem areas and then clear/reset codes after proper repair. Turn Off Check Engine Light: When your car detects an emission related problem, the check engine light will be turned on. maybe it's just a fuel cap that's not screwed on or bad parts like spark plugs, ignition coils, etc. need to be replaced? Using the Autel MS309 scan tool, you can read the code to quickly find out why the check engine light is on and reset it.so you can save money.