I have a trane xe 80 and my high temp limit switch open led flashing light code appeared.
Trane fan limit switch.
Thought that was the fix but the burners went out and the same code again.
I changed out the filters and it started up again.
This means that this limit switch opens and cuts off the gas burners when the temperature inside the furnace heat exchanger reaches 190 f and closes back to allow the burners to come back on when the heat exchanger reaches a temperature of 160 degrees f.
The high temp limit switches usually have a manual reset button that needs to be pressed to reset.
I did some research and thought it was due to a clogged filter.
Fan limit switch q a 5 furnace fan limit control troubleshooting.
This is used so that cold air is not blown into a house waiting for the gas flames to heat up enough before the blower turns on.
I would try a reset it may have been a fluke that it tripped if the reset dosent trip again it is probably fine.
The specifications on the furnace limit switch are thermal limit open 190 f close 160 deg f.