RAM 1500 2021 — technical service bulletin
Bulletin 18-053-26 · NHTSA communication 11032831 · issued May 5, 2026
Technical service bulletin
communication type
Electrical System
component
2021
model years
1
vehicle entries
Official summary
Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set the following Diagnostic Trouble Code (DTC): ● P219A - Bank 1 Air-Fuel Ratio Imbalance Bank 1. Customers may also comment on the following: ● **Potential under run or stall when the vehicle utilizes the Trailer Reverse Steering Control feature and is connected to a trailer attempting to backup.** This bulletin involves reprogramming the PCM with the latest available software.
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.