{"nhtsa_id":634889,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2002-10-10","date":"2002-05-01","document_id":"020139003","mfr_campaign":null,"replaces":null,"component":"VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM","mfr_system":null,"summary":"CONCERNS WITH EXT AND XL MODELS EXHIBITING INOPERATIVE REAR HVAC CONTROLS AND / OR DIAGNOSTIC TROUBLE CODE B0150. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/634889","components":[{"id":"visibility","name":"Glass, wipers and mirrors","parent":null},{"id":"hvac","name":"Heating and air conditioning","parent":null}],"codes":["B0150"],"topics":[],"vehicles":[{"make":"CHEVROLET","model":"TRAILBLAZER","year_from":2002,"year_to":2002,"match":"exact","vehicle_ids":["2002_chevrolet_trailblazer"]},{"make":"GMC","model":"ENVOY","year_from":2002,"year_to":2002,"match":"exact","vehicle_ids":["2002_gmc_envoy"]}],"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":[]}