{"nhtsa_id":612491,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2000-06-08","date":"2000-03-01","document_id":"000502","mfr_campaign":null,"replaces":"000502","component":"POWER TRAIN:AUTOMATIC TRANSMISSION","mfr_system":null,"summary":"SOME VIN Z VEHICLES WITH VIN 185138 AND BELOW AND WITH TRANSFER CASES BUILT BEFORE MAY 7, 1999 MAY EXHIBIT A TRANSMISSION DEFAULT TO SECOND GEAR, ERRATIC SHIFTING, FAILURE OF THE SPEEDOMETER AND DIAGNOSTIC TROUBLE CODE P1871. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/612491","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null},{"id":"automatic-transmission","name":"Automatic transmission","parent":"powertrain"}],"codes":["P1871"],"topics":[],"vehicles":[{"make":"AM GENERAL","model":"HUMMER","year_from":1996,"year_to":1999,"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":[]}