{"nhtsa_id":601159,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1998-07-06","date":"1998-02-01","document_id":"985471","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:ENGINE","mfr_system":null,"summary":"GENERAL INFORMATION ON THE OPTIMIZED IDLE FEATURE ON VEHICLES EQUIPPED WITH A DDEC III ENGINE AND ESS. *YC","document":null,"url":"https://open.wenmarpro.com/bulletins/601159","components":[{"id":"engine","name":"Engine","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"FREIGHTLINER","model":"CENTURY","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":[]}