RAM 2500 2019–2021 — technical service bulletin
Bulletin S2121000010 · NHTSA communication 10230173 · issued Jul 1, 2021
Technical service bulletin
communication type
Power Train
component
2019–2021
model years
12
vehicle entries
Official summary
Service 4WD Lamp On, 4WD System Does Not Work, 4WD Service Lamp Flashing, Front Axle Disconnect Does Not Engage Or Disengage
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.