{"nhtsa_id":10199483,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2021-08-02","date":"2021-07-02","document_id":"21U04","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN; ELECTRICAL SYSTEM","mfr_system":null,"summary":"In some of the effected vehicles the active noise cancelation (ANC) and electronic sound enhancement (ESE) features were not activated in the audio control module (ACM). This can cause undesirable powertrain sounds inside the vehicle, and less than optimal speaker sound from ST products, resulting in customer dissatisfaction.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10199483-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10199483-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10199483","components":[{"id":"electrical","name":"Electrical system","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"FORD","model":"EXPLORER","year_from":2021,"year_to":2021,"match":"exact","vehicle_ids":["2021_ford_explorer"]},{"make":"LINCOLN","model":"AVIATOR","year_from":2021,"year_to":2021,"match":"exact","vehicle_ids":["2021_lincoln_aviator"]}],"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":[]}