Chevrolet 3500 2021–2022 — technical service bulletin
Bulletin N222380840 · NHTSA communication 10226235 · issued Nov 17, 2022
Technical service bulletin
communication type
Power Train
component
2021–2022
model years
5
vehicle entries
Official summary
General Motors has decided to conduct a Voluntary Emissions Recall on certain vehicles with a 6.6L engine (RPO L8T). The Transmission Control Module (TCM) in these vehicles may have been service reprogrammed with incorrect calibrations. If this occurred, the transmission shift quality and timing could be degraded. Dealers are to reprogram the TCM.
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.