Freightliner Cascadia 2018–2021 — technical service bulletin
Bulletin SB54-331 · NHTSA communication 10177693 · issued Jul 30, 2020
Technical service bulletin
communication type
Electrical System
component
2018–2021
model years
4
vehicle entries
Official summary
Freightliner Service Bulletin for Updated ULB Control Unit for LED Headlamps. New Cascadia vehicles with light emitting diode (LED) headlamps built from January 1, 2017 through February 17, 2020 may experience intermittent disabled headlamps due to an issue with the universal light ballast (ULB). The LED headlamps can turn off if the supply voltage drops below approximately 9V. This low voltage commonly and momentarily occurs when cranking the engine on a vehicle with batteries that are not fully charged. The momentary low voltage may cause the electronic ULB control unit to malfunction. The U
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.