{"nhtsa_id":636424,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2002-11-08","date":"2002-03-01","document_id":"020508","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"summary":"INOPERATIVE OR INACCURATE SPEEDOMETER, 4X4 LAMP ILLUMINATED, AND / OR DIAGNOSTIC TROUBLE CODE P1635 OR P1639 PRESENT AFTER POWERTRAIN CONTROL MODULE (PCM) OR INSTRUMENT CLUSTER REPLACEMENT. 1999-2002 VARIOUS FORD VEHICLES. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/636424","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":["P1635","P1639"],"topics":[],"vehicles":[{"make":"FORD","model":"FORD","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":[]}