{"nhtsa_id":11017434,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-05-01","date":"2025-04-08","document_id":"09-131-25","mfr_campaign":null,"replaces":null,"component":"ENGINE; ELECTRICAL SYSTEM","mfr_system":null,"summary":"This bulletin announces the diagnostic procedures and availability of reprograming files to rectify the following Diagnostic Trouble Codes (DTCs). The ELCM may accumulate condensation causing the inaccurate detection of P2404. P0420 may become falsely detected due to unstable combustion caused by a downshift. The new reprogramming files contains enhanced software allowing for condensation conditions and downshift rotational speeds be more accurately detected by the Engine Control Module (ECM).","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11017434-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11017434-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11017434","components":[{"id":"electrical","name":"Electrical system","parent":null},{"id":"engine","name":"Engine","parent":null}],"codes":["P0420","P2404"],"topics":[],"vehicles":[{"make":"SUBARU","model":"WRX STI","year_from":2015,"year_to":2021,"match":"base","vehicle_ids":["2015_subaru_wrx","2016_subaru_wrx","2017_subaru_wrx","2018_subaru_wrx","2019_subaru_wrx","2020_subaru_wrx","2021_subaru_wrx"]}],"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":[]}