{"nhtsa_id":11028091,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-02-03","date":"2026-01-08","document_id":"01-001-26","mfr_campaign":null,"replaces":null,"component":"ENGINE","mfr_system":"Cooling System","summary":"Some customers may experience a check engine light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: Engine takes longer to warm up. • Engine temperature gauge fluctuates. • Low coolant temperature indicator (blue) light stays on longer or turns on while driving. • Poor heater performance, especially at idle. • This concern may be caused if the coolant control valve fail-safe thermostat opens at a temperature lower than the normal temperature due to a deformation of the thermostat diaphragm. To eliminate the concern, the water flow control valve specification has been modified.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11028091-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11028091-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11028091","components":[{"id":"engine","name":"Engine","parent":null}],"codes":["P0126"],"topics":[],"vehicles":[{"make":"MAZDA","model":"CX-3","year_from":2019,"year_to":2021,"match":"exact","vehicle_ids":["2019_mazda_cx-3","2020_mazda_cx-3","2021_mazda_cx-3"]},{"make":"MAZDA","model":"CX-30","year_from":2020,"year_to":2023,"match":"exact","vehicle_ids":["2020_mazda_cx-30","2021_mazda_cx-30","2022_mazda_cx-30","2023_mazda_cx-30"]},{"make":"MAZDA","model":"CX-5","year_from":2018,"year_to":2025,"match":"exact","vehicle_ids":["2018_mazda_cx-5","2019_mazda_cx-5","2020_mazda_cx-5","2021_mazda_cx-5","2022_mazda_cx-5","2023_mazda_cx-5","2024_mazda_cx-5","2025_mazda_cx-5"]},{"make":"MAZDA","model":"MAZDA3","year_from":2019,"year_to":2023,"match":"exact","vehicle_ids":["2019_mazda_mazda3","2020_mazda_mazda3","2021_mazda_mazda3","2022_mazda_mazda3","2023_mazda_mazda3"]},{"make":"MAZDA","model":"MAZDA6","year_from":2018,"year_to":2021,"match":"exact","vehicle_ids":["2018_mazda_mazda6","2019_mazda_mazda6","2020_mazda_mazda6","2021_mazda_mazda6"]}],"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":[]}