Where Is Your Harley-Davidson® Diagnostic Port?

Posted by Lisa DiFalco on

diagnostic port for Harley-Davidson bike Diagnostica

Image of a 4-pin diagnostic port on a standard Harley-Davidson bike. Look for a connector that is light gray and has a black rubber plug installed. Tools may be necessary to remove a cover and gain access.


There may come a time in your life when you need to locate the diagnostic port on your Harley. The problem is that finding it is not always as simple as what one may think. The diagnostic port location on Harley-Davidson bikes differs by model and year. Our team provides the following information to make the process clearer for those looking to use their port to do some easy diagnostics or to make changes to the systems on their bike, as when they want to tune their Harley.

Where Is the Darn Thing?

Let’s get right into it. A Harley owner may want to check with their service manual for the exact location of their diagnostic port. That being said, the location for the diagnostic port when sitting on your ride is:

  • Behind the side cover, on the right side and in front of any saddle bags for Touring bikes manufactured from 2001-2007. After 2008, the diagnostic port may be found on left side with all other aspects being the same.
  • Under the seat for all model years of Softail bikes.
  • On the left side of the bike, below the seat and behind a Dyna bike’s rectangular cover for all models years.
  • Either on the left or right side for all V-Rod Bikes and all model years. The location should be between the forks and the frame and behind the triangular cover.
  • On the left side for XL (Sportster) Bikes from 2007-2018. Find it below the seat and behind the side cover.
  • On the right side for Harley Street Bikes from 2015-2018. Look below the seat and behind the side cover.

For proper diagnosis using the Motorscan smartphone diagnostic tool, it is important to find and plug into the diagnostic port on a standard and unmodified bike. Check the compatibility guide prior to purchasing and use the information above to find the location of the diagnostic port on a specific model and year of bike.

Avoid the Lookalike

You may already know by now that there is another port on Harley-Davidson bikes for software updates. This port is not connected to the battery and therefore any diagnostic device plugged into it requiring the engine to run will not work. Be sure to locate and use the actual diagnostic port on your Harley-Davidson when using the Motorscan smartphone diagnostic tool. Have additional questions? Comment below, email news@diagnostica.tools or tweet @DiagnosticaNews.






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