Jeep Grand Cherokee 2021 — technical service bulletin
Bulletin 0804122 · NHTSA communication 10229114 · issued Mar 1, 2022
Technical service bulletin
communication type
Back Over Prevention
component
2021
model years
1
vehicle entries
Official summary
Flash: Amplifier (AMP) Diagnostic and System Updates This bulletin involves reprogramming the AMP with the latest available software. Customers may experience the following:Active Noise Cancellation (ANC) drone noise at 950 between 1,000 RPM, during a start up.The AMP may set B221F-00 (Amplifier Internal) erroneously, it does not affect Active Noise Cancelation (ANC) performance. If B221F-00 is a stored fault update the AMP with appropriate software. If fault is active, follow normal DTC diagnostics.
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.