TSB 01-003-25B — Mazda Service bulletin
01-003-25B is a service bulletin on file with NHTSA for 2 Mazda models, 2018–2021 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. 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…
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Vehicles and model years 01-003-25B names
| Vehicle | Model years |
|---|---|
| Mazda CX-5 | 2018, 2019, 2020 |
| Mazda Mazda6 | 2018, 2019, 2020, 2021 |
Every document filed under 01-003-25B
| Document ID | Filed | Type |
|---|---|---|
| 01-003-25b | December 24, 2025 | Service bulletin |
What 01-003-25B covers
Engine — the component vocabulary NHTSA files this communication under.
Questions buyers ask
What is TSB 01-003-25B?
01-003-25B is a service bulletin filed with NHTSA by Mazda, covering 2 Mazda models across the 2018–2021 model years. NHTSA's summary reads: 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…
Which vehicles does 01-003-25B cover?
NHTSA's file names Mazda CX-5 (2018–2020); Mazda Mazda6 (2018–2021). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.
Is TSB 01-003-25B a recall, and is the repair free?
No. 01-003-25B is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.
How do I get the full text of 01-003-25B?
Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under 01-003-25B, its date, and NHTSA's own summary from the public file.
Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under 01-003-25B. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.