Mazda issued an emissions recall due to a problem with the Swirl Shutter Valve; this would cause the Check Engine light to illuminate.
2010 Mazda Mazda6 Problem Reports
Newest 2010 Mazda Mazda6 Problem Reports
Mazda just replaced my transmission under warranty due to it slipping from 1st to 2nd gear
The engine may overheat due to erratic engine cooling fan operation as a result of a faulty cooling fan control module. Replacement of the fan control module would be necessary to correct this condition. Our technicians tell us the Mazda may provide assistance with the cost of this repair.