{"nhtsa_id":10190020,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2021-04-08","date":"2021-03-10","document_id":"DT12 Trans Chafe","mfr_campaign":null,"replaces":null,"component":"EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN","mfr_system":null,"summary":"DTNA received a field notification on multiple units regarding diagnostic fault codes that were found to be causing issues to the After Treatment Control Module (ACM). These fault codes indicated that the ACM communication message was not received by the Motor Control Module (MCM) which in certain cases, led to a 25% engine de-rate situation. Further diagnosis revealed that the DT12 wiring harness was chafing and contacting the transmission TCU case. To reduce potential chafing areas, the proposed short-term containment was to route the wiring harness using additional tie straps. This communication applies to Freightliner and Western Star vehicles built with DT12 transmissions.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10190020-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10190020-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10190020","components":[{"id":"equipment","name":"Equipment and accessories","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"FREIGHTLINER","model":"CASCADIA","year_from":2014,"year_to":2022,"match":"exact","vehicle_ids":["2014_freightliner_cascadia","2015_freightliner_cascadia","2016_freightliner_cascadia","2017_freightliner_cascadia","2018_freightliner_cascadia","2019_freightliner_cascadia","2020_freightliner_cascadia","2021_freightliner_cascadia","2022_freightliner_cascadia"]},{"make":"WESTERN STAR","model":"4900","year_from":2014,"year_to":2021,"match":"exact","vehicle_ids":["2014_western-star_4900","2015_western-star_4900","2016_western-star_4900","2017_western-star_4900","2018_western-star_4900","2019_western-star_4900","2020_western-star_4900","2021_western-star_4900"]},{"make":"WESTERN STAR","model":"49X","year_from":2021,"year_to":2021,"match":null,"vehicle_ids":[]},{"make":"WESTERN STAR","model":"5700","year_from":2014,"year_to":2022,"match":"exact","vehicle_ids":["2014_western-star_5700","2015_western-star_5700","2016_western-star_5700","2017_western-star_5700","2018_western-star_5700","2019_western-star_5700","2020_western-star_5700","2021_western-star_5700","2022_western-star_5700"]}],"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":[]}