{"nhtsa_id":10134778,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2018-04-23","date":"2018-03-08","document_id":"Cummins 9L Gas","mfr_campaign":null,"replaces":null,"component":"ENGINE","mfr_system":null,"summary":"Mack Trucks has identified a condition with 2018 L9N Cummins Westport, Inc. (CWI) natural gas engines when installed in a bare Mack chassis which may cause an increase in engine speed when the truck decelerates close to idle speed.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2018/MC-10134778-9999.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2018/MC-10134778-0001.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10134778","components":[{"id":"engine","name":"Engine","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"MACK","model":"MACK","year_from":null,"year_to":null,"match":null,"vehicle_ids":[]}],"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":[]}