I'm glad I found this thread I have had similar issues with multiple different mazdas. The first issue was easily solved by replacing the actual brake pedal switch. I was actually pretty impressed at how affordable that part was and it completely solved the problem. On the other vehicle there was a sensor in the wheel I believe it ended up being ABS and that was losing connectivity and not returning any data. That was a slightly more costly repair however it also solved the problem. It seems that on a Mazda these lights tend to come on when there is a failure in any breaking related circuit. My troubleshooting for this problem starts with brake fluid, break pedal switch, associated relays, then inspection of components with the wheels off. I do find it interesting that this same group of warning lights is triggered by what in my opinion seems to be any loss of electrical communication for lack of a better word with components of the braking system. Thanks to everyone that replied to this thread it really helped me put together a troubleshooting routine for the mazdas in my family of which there are multiple.