Freightliner Cascadia 2017–2021 — technical service bulletin
Bulletin SB54-338 · NHTSA communication 10184869 · issued Dec 29, 2020
Technical service bulletin
communication type
Equipment
component
2017–2021
model years
5
vehicle entries
Official summary
Freightliner Service Bulletin for Front HVAC Evaporator Freezing and Espar Heater Cool Down Algorithm. New Cascadia vehicles with sleeper cabs may become extremely cold when in A/C mode, which can lead to reduced airflow as a result of internal ice buildup at the evaporator. Durability of the Espar D5 heater system when paired with the battery parked HVAC system (BPHS) can be improved by applying "cool down" software to the parked control unit (PCU).
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.