Mazda CX-5 2018–2019 — technical service bulletin
Bulletin SA-015-19a · NHTSA communication 10160578 · issued May 20, 2019
Technical service bulletin
communication type
Engine
component
2018–2019
model years
4
vehicle entries
Official summary
If you receive a customer concern with the check engine light coming on and DTC P3400 (cylinder deactivation system malfunction) stored, perform the inspection in the Repair Procedure.
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.