— Mazda is recalling more than 304,000 vehicles because problems with the powertrain control modules can cause the engines to stall.
Recalled are the 2018-2019 Mazda CX-5, 2018-2019 Mazda6 and 2019 Mazda3 to repair problems that cause the engines to lose power or stall.
Mazda received a report in January 2018 about engine noise and was told the cylinder intake valve rocker arm fell off, then two months later a second report said an engine was running rough.
The automaker opened an investigation and determined a possible root cause in November 2018.
Engineers found problems with the oil pressure control signal response, but additional investigation also showed there were problems with the programming of the "transition between all four cylinder operation and two cylinder deactivation modes..."
As a result, an intake valve rocker arm may come out of position and make contact with internal engine parts and cause an engine misfire, a loss of engine power and illuminated warning lights.
Mazda changed the design of the powertrain control module and improved the software during production, but now those fixes need to be applied to the recalled vehicles.
About 262,000 vehicles are recalled in the U.S. and more than 42,600 Mazda vehicles are recalled in Canada.
All the vehicles were manufactured in Japan except for the 2019 Mazda3 vehicles which were built in Mexico. Mazda says it doesn't know of any crashes, injuries or deaths related to stalled engines.
Mazda dealers will reprogram the powertrain control modules with improved hydraulic valve adjustment control software once the recall begins August 26, 2019.
Affected Mazda customers may call 800-222-5500. Mazda's number for this recall is 3719F.