{"nhtsa_id":621174,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2001-09-10","date":"2001-06-01","document_id":"54139","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM","mfr_system":null,"summary":"SOME VEHICLES MAY EXHIBIT PROBLEMS WITH THE THERMOCOUPLE AND / OR PYROMETER. THIS BULLETIN PROVIDES TROUBLESHOOTING PROCEDURES FOR TESTING ISSPRO THERMOCOUPLES, PYROMETERS, AND RELATED WIRING. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/621174","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"FREIGHTLINER","model":"BUSINESS CLASS","year_from":null,"year_to":null,"match":null,"vehicle_ids":[]},{"make":"FREIGHTLINER","model":"FLB","year_from":null,"year_to":null,"match":"exact","vehicle_ids":[]},{"make":"FREIGHTLINER","model":"FLD","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":[]}