Mazda CX-3 2018–2020 — technical service bulletin
Bulletin SA-035-20b · NHTSA communication 10185185 · issued Dec 2, 2020
Technical service bulletin
communication type
Engine and Engine Cooling
component
2018–2020
model years
12
vehicle entries
Official summary
Some customers may experience the CHECK ENGINE LIGHT ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: The engine takes longer to warm up. The engine temperature gauge fluctuates. The low coolant temperature indicator (blue) light stays on longer or comes on while driving. Poor heater performance, especially at idle.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.