Freightliner Cascadia 2018–2021 — technical service bulletin
Bulletin SB54-331 · NHTSA communication 10179872 · issued Sep 10, 2020
Technical service bulletin
communication type
Visibility
component
2018–2021
model years
4
vehicle entries
Official summary
Updated Freightliner Service Bulletin for Updated ULB Control Unit for LED Headlamps. This bulletin replaces the version dated July 30, 2020. Information about a reman part has been added. 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 a
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.