Electronic troubleshooting equipment manufacturer Diagnostica has announced an adapter that will allow owners of Harley-Davidsons to use their smartphones as a trouble-code scanner. The adapters come in two sizes — a four-pin type for the older OBD DLCs and Delphi ECUs, and a six-pin unit to connect up to the CAN-Bus port on the newer models. A plug-and-play unit, it utilizes a phone app that allows the user to scan for codes, erase said codes and view many of the other critical metrics usually available only to a service department. Needless to say, this little gem can save you the time, money, and aggravation associated with visits to the service department and can act as an enabler for would-be shade-tree mechanics. Even though the device will set you back a whopping $299, I think we can all agree that it won’t take long to amortize that expense even if you live in areas with relatively low hourly labor rates. On the downside, I can say from experience that the codes do not necessarily tell you what part to replace, they only tell you the symptoms that have been recorded, so it isn’t a silver bullet by any means, but it does give you a starting point. Besides, letting the shop do the work can be expensive, but asking questions based on your readings is free, and the answers can plug any information gaps for most middling home mechanics.