One problem related to brake light on has been reported for the 2014 Mazda MAZDA6. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2014 Mazda MAZDA6 based on all problems reported for the 2014 MAZDA6.
A year ago I took my car for a recall that had to do with the handbrake somehow rusting out where it sits in the rear brake calipers. They inspected the calipers and told me they had to order parts. I never received a call. The next time I went back I asked about it and they said it was fix. After the visit they recommended to replace the rear brake calipers. The vehicle is a manual and is to the point where the hand brake does not work at all. It runs the risk of rolling away if the transmission fails or it comes out of gear. It is clearly stated in NHTSA #17v-393 and I have called Mazda corporate who told me it doesn't have to do with the calipers ("your Mazda dealer will check the parking brake actuator shafts inside the left and right rear brake calipers. "). Mazda reference number 1-2080181118. Also because of the rust the handbrake is lose so if you use cruise control the handle can accidental pull up enough to ignite the handbrake light and make the car automatically turn off cruise control which is surprising and could cause the driver to crash.