What are Harley Davidson trouble codes?
What the codes cover
Harley-Davidson motorcycles store codes for engine management, fuel injection, ignition, sensors, and some electronic accessories. Some codes follow standard OBD II style formats, while others are specific to Harley systems. The code list depends heavily on the model year and engine.
How to read them
On many fuel-injected models, a scanner or dealer tool connects to the diagnostic port and displays active and stored codes. Some older models show codes by flashing a dash lamp after a specific procedure. Note the model year, engine size, and any recent modifications before you start, since these affect which steps apply.
The owner's or service manual for your bike is the best starting point for the correct procedure and code list.
- Check the service manual for your exact model year
- Record each code and whether it is active or stored
- Clear codes only after the fault is repaired and verified
Watch out for aftermarket parts
Aftermarket exhausts, air filters, or tuners can trigger codes or change how sensors read. Clearing codes can also remove freeze frame data that helps with diagnosis. Write down the original codes before any repair or reset.
Common mistakes
- Assuming a code means a specific part has failed without testing it.
- Clearing codes before writing them down, which removes useful clues.
