{"nhtsa_id":11026901,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-01-03","date":"2025-12-04","document_id":"01-003-25a","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/2025/MC-11026901-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11026901-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11026901","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":[]}