{"nhtsa_id":620070,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2001-07-11","date":"2001-05-18","document_id":"2400701","mfr_campaign":null,"replaces":null,"component":"VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM","mfr_system":null,"summary":"A CUSTOMER MAY EXPERIENCE COLER OR WARMER THAN DESIRED AIR TEMPERATURES COMING FROM THE VEHICLE HVAC SYSTEM VENTS. THIS CHANGE IN AIR TEMPERATURE MAY OCCUR GRADUALLY OVER TIME AND ONLY ON VEHICLES EQUIPPED WITH THE AUTOMATIC ZONE CONTROL (AZC) HVAC SYSTEM. THIS BULLETIN INVOLVES THE REPLACEMENT OF THE AUTOMATIC ZONE CONTROL ASSEMBLY. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/620070","components":[{"id":"visibility","name":"Glass, wipers and mirrors","parent":null},{"id":"hvac","name":"Heating and air conditioning","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"JEEP","model":"GRAND CHEROKEE","year_from":1999,"year_to":2001,"match":"exact","vehicle_ids":["1999_jeep_grand-cherokee","2000_jeep_grand-cherokee","2001_jeep_grand-cherokee"]}],"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":[]}