{"nhtsa_id":10048500,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2012-12-20","date":"2012-11-06","document_id":"TIB-26-023","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM:SOFTWARE; ENGINE; POWER TRAIN:AUTOMATIC TRANSMISSION","mfr_system":null,"summary":"KENWORTH: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. TRANSMISSION DOES NOT AUTOMATICALLY UPSHIFT WHEN HIGH IDLE SPEED OF ENGINE IS EXCEEDED DUE TO LACK OF PROPER CALIBRATION OF TRANSMISSION FOR-ENGINE. MODELS 2010-2012 T660, T700 AND T800. *PE","document":null,"url":"https://open.wenmarpro.com/bulletins/10048500","components":[{"id":"electrical","name":"Electrical system","parent":null},{"id":"engine","name":"Engine","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null},{"id":"automatic-transmission","name":"Automatic transmission","parent":"powertrain"},{"id":"software","name":"Software","parent":"electrical"}],"codes":[],"topics":[],"vehicles":[{"make":"KENWORTH","model":"T660","year_from":2010,"year_to":2012,"match":null,"vehicle_ids":[]},{"make":"KENWORTH","model":"T700","year_from":2010,"year_to":2012,"match":null,"vehicle_ids":[]},{"make":"KENWORTH","model":"T800","year_from":2010,"year_to":2012,"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":[]}