AI Damage2021 Harley-Davidson FLH: common problems
The maker issued 48 service bulletins for this year. Details by component below, with sources.
Key figures
- Technical service bulletins (TSB)
- 48
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Electrical system | 0 | 0 | 30 |
| Powertrain | 0 | 0 | 19 |
| Engine | 0 | 0 | 14 |
| Vehicle speed control | 0 | 0 | 11 |
| Fuel/propulsion system | 0 | 0 | 8 |
| Engine and cooling | 0 | 0 | 7 |
| Equipment | 0 | 0 | 6 |
| Wheels | 0 | 0 | 5 |
| Electronic stability control | 0 | 0 | 2 |
| Exterior lighting | 0 | 0 | 1 |
| Fuel system | 0 | 0 | 1 |
| Other | 0 | 0 | 32 |
What to check before buying
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Vehicle speed control. Accelerator pedal, cruise control, throttle codes.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- SERVICE BULLETIN M1490 (V 26.9.4)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1733
COSMETIC CYLINDER STAINING (ALL MILWAUKEE-EIGHT MODELS). PURPOSE: Initial release. This bulletin informs dealers that cosmetic staining or etching on the inside of the cylinder bore does not have an impact on engine…
- SERVICE BULLETIN M1490 (V 26.8.3)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1490 (V 26.7.3)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1490 (V 26.6.2)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1679
AFTERMARKET EXHAUST HEADER DEBRIS. PURPOSE: Initial release. This bulletin informs dealers that Harley-Davidson has identified instances of premature engine failure due to abrasive particle wear, specifically from…
- SERVICE BULLETIN M1490 (V 26.5.2)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1713 (REV C)
DTII UPDATE PROCEDURE FOR SOFTWARE VERSION (26.4.3). PURPOSE: Revision C. This bulletin informs dealers that an issue was discovered in the Digital Technician II (DT II) software version (26.0.2), released on November…
- SERVICE BULLETIN M1490 (V 26.4.3)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1713 (REV B)
DTII UPDATE PROCEDURE FOR SOFTWARE VERSION (26.3.2). PURPOSE: Revision B. This bulletin informs dealers that an issue was discovered in the Digital Technician II (DT II) software version (26.0.2), released on November…
- SERVICE BULLETIN M1490 (V 26.3.2)
DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER…
- SERVICE BULLETIN M1713
DTII UPDATE PROCEDURE FOR SOFTWARE VERSION (26.1.5). PURPOSE: Initial Release. This bulletin informs dealers that an issue was discovered in the Digital Technician II (DT II) software version (26.0.2), released on…
NHTSA lists 48 bulletins for this year; the 12 newest are shown here.
Questions and answers
What are the most common problems with the 2021 Harley-Davidson FLH?
There are no owner complaints in the NHTSA data for this year; the data comes from 48 manufacturer service bulletins.
How many service bulletins (TSB) were issued for the 2021 Harley-Davidson FLH?
NHTSA lists 48 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2021 Harley-Davidson FLH from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2021 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-04.