Jeep Grand Cherokee 2021 — technical service bulletin
Bulletin 0804322REVA · NHTSA communication 10220791 · issued Mar 10, 2022
Technical service bulletin
communication type
Visibility
component
2021
model years
1
vehicle entries
Official summary
Flash: Heating Ventilation and Air Conditioning (HVAC) Updates This bulletin involves reprogramming the HVAC module with the latest available software. Customers may experience the following:High pitch whistle coming from the dash when the blower motor is turned on.High pitch whistle originated from the defroster door when the HVAC unit in either Hi-Level (panel and defrost) or Bi-Level (panel and floor) modes. May be worsened when running the front airflow at blower bar 1-2 and rear airflow at blower bar 5-7.
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.