2020–2022 Thomas Built Buses Saf-T-Liner Efx, 2020–2022 Thomas Built Buses Saf-T-Liner HDX Recall: Nut for the power cable stud on the alternator may not have been tightened…
NHTSA campaign 21V850000 · Electrical System · filed Nov 2, 2021 · verified Jul 30, 2026
The defect
Daimler Trucks North America, LLC (DTNA) is recalling certain 2020-2022 Thomas Built EFX and HDX school buses. The nut for the power cable stud on the alternator may not have been tightened properly, which can cause a loose cable connection.
The risk
A loose power cable connection may cause electrical arcing, which can increase the risk of a fire.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →The fix — what to do
Dealers will inspect the alternator power cable connection and tighten it if necessary, free of charge. Owner notification letters were mailed on December 17, 2021. Owners may contact DTNA customer service at 1-800-547-0712. DTNA's number for this recall is FL904.
Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.nhtsa.gov.
Affected vehicles
| Make | Model | Model years |
|---|---|---|
| Thomas Built Buses | Saf-T-Liner Efx | 2020, 2021, 2022 |
| Thomas Built Buses | Saf-T-Liner HDX | 2020, 2021, 2022 |
Related recalls
More Thomas Built Buses Saf-T-Liner Efx recalls
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- 2025–2026 Thomas Built Buses Saf-T-Liner C2 and 4 other models — Tie rod castle nut and cotter pin may not be installed…
- 2019–2022 Thomas Built Buses Minotour DRW and 5 other models — Emergency Exit Label lettering is too small and may be…
Other campaigns involving Thomas Built Buses vehicles
- 2026–2027 Thomas Built Buses Saf-T-Liner EFX2 and 1 other model — Entrance door may fail to open or close when the switch is…
- 2026–2027 Thomas Built Buses Saf-T-Liner HDX2 — Entrance door may fail to open or close when the switch is…
- 2027 Thomas Built Buses Saf-T-Liner HDX2 — Front and mid-body interior joints may have been…
All Thomas Built Buses Saf-T-Liner Efx recalls → · All Thomas Built Buses recalls →
Source: NHTSA recall database, campaign 21V850000 (manufacturer number FL904). Data last verified Jul 30, 2026.