Type a Harley-Davidson diagnostic trouble code (for example P0562) to see what it means, how serious it is, and the most common causes – or browse the full list by system. Built from standard OBD-II definitions plus Harley-Davidson electrical diagnostic manuals. Free, no signup.
Harley-Davidson Diagnostic Code (DTC) Decoder
When your check-engine or security light flashes a code - or a scanner reads one - type it below to find out what it means, how serious it is, and the most likely causes. Based on standard OBD-II definitions and Harley-Davidson electrical diagnostic manuals.
Method 1 - Odometer flash (no scanner required, most 2001+ EFI models): Hold the trip reset button, turn ignition ON (engine off). Keep holding until the odometer displays a code like P0562. Release, press again to scroll through all stored codes. Codes clear when you cycle through to the end or after repair.
Method 2 - HD-compatible scanner: Models from ~2001 onward use a standard OBD-II/J1850 data port (often under the seat or near the battery). A generic ELM327 adapter may read some codes; for full coverage including BCM/ABS/security codes, use an HD-specific scan tool or software.
Code format: P = Powertrain, B = Body, C = Chassis, U = Network/Communication. Followed by 4 digits.
How to read a Harley code without a scanner
On many 2001-and-later EFI Harley models you can read stored codes through the odometer: hold the trip-reset button, turn the ignition ON (engine off), and keep holding until a code appears. Press again to scroll through stored codes. A code points to a circuit or symptom, not a confirmed faulty part – the decoder above explains the likely causes and what to check next.
Related diagnostics
Ignition coil codes (P1351-P1358) are common – see Harley bad coil symptoms. Confirm your model and year with the free VIN Decoder, and budget repairs with our guide to Harley maintenance costs.