Diagnostic Trouble Codes
Diagnostic Trouble Codes (DTCs) are captured/stored by your Harley's ECU when a problem occurs so that a tech can diagnose and hopefully fix the problem later on. GaugeFace lets you look up codes and shows a nice description of each code.
Even better, GaugeFace also Reads the DTC's from your ECU and even lets you Erase them too! Once any DTC's are detected you can also create an email message with the DTC's listed automatically in case you are on the road and need help quickly.
You can buy a standalone Service Code Reader from Harley for $150 USD to just Read and Erase DTCs or, if you are into getting a custom gauge and charging your iPhone or iPod touch, get the GaugeFace app and hardware adapter instead and get much more value!