There are many reasons for a vehicle to enter limp-home mode. One of them, of course is transmission temperature, but there are lots of things being monitored, from the temperature of the engine oil, coolant temperature, oil level and even the operating temperature of the EGR valve (which is often water-cooled in vehicles like the Mazda). The point being that even though the transmission entered limp-home mode, the actual problem may have been elsewhere, but the vehicle’s computer believed that shutting down much of the transmission’s functions would preserve and protect the rest of the driveline. Don’t forget, either, that there are many things – a failed solenoid, low fluid level, even a faulty wiring connection or earth – that can cause a transmission limp-home event beyond actual overheating.