{"nhtsa_id":10220770,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2022-09-26","date":"2022-03-01","document_id":"0804122","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM","mfr_system":null,"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.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2022/MC-10220770-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2022/MC-10220770-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10220770","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":["B221F"],"topics":[],"vehicles":[{"make":"JEEP","model":"GRAND CHEROKEE","year_from":2021,"year_to":2021,"match":"exact","vehicle_ids":["2021_jeep_grand-cherokee"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}