Freightliner Cascadia 2017–2020 — technical service bulletin
Bulletin SB54-322 · NHTSA communication 10169529 · issued Dec 19, 2019
Technical service bulletin
communication type
Equipment
component
2017–2020
model years
4
vehicle entries
Official summary
Service Bulletin for Adjusting Automatic Temperature Control Range with Optimized Idle. Front and rear HVAC systems operate as independent constant outlet temperature control (COTC) systems when Optimized Idle (OI) is not armed.
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.