{"nhtsa_id":11031807,"type":"over_the_air","type_name":"Over-the-air update","date_added":"2026-04-30","date":"2026-04-14","document_id":"661.30","mfr_campaign":"661.30","replaces":null,"component":"UNKNOWN OR OTHER","mfr_system":"ECM: ECM (Engine Control Module)","summary":"• Fixes to help extend coolant valve life through diagnostic changes.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11031807-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11031807-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11031807","components":[],"codes":[],"topics":[],"vehicles":[{"make":"CHEVROLET","model":"SILVERADO 1500","year_from":2023,"year_to":2023,"match":"base","vehicle_ids":["2023_chevrolet_silverado"]},{"make":"GMC","model":"SIERRA 1500","year_from":2023,"year_to":2023,"match":"base","vehicle_ids":["2023_gmc_sierra"]}],"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":[]}