{"nhtsa_id":623754,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2001-10-30","date":"2001-06-04","document_id":"040601","mfr_campaign":null,"replaces":null,"component":"VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM","mfr_system":null,"summary":"VEHICLES MAY EXPERIENCE UNWANTED AIR ENTRY THROUGH THE VENTILATION SYSTEM. *SLC","document":null,"url":"https://open.wenmarpro.com/bulletins/623754","components":[{"id":"visibility","name":"Glass, wipers and mirrors","parent":null},{"id":"hvac","name":"Heating and air conditioning","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"GMC","model":"PICKUP","year_from":1999,"year_to":2001,"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":[]}