As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) A/C WAS REPORTED BY FLIGHT CREW TO HAVE HAD A BRAKE TEMP WARNING DURING CLIMB OUT. AIRCRAFT RETURNED AFTER DECLARING EMERGENCY WITH ATC. FLIGHT IS BACK ON THE GROUND WITHOUT FURTHER INCIDENT AND BACK AT THE GATE. CORRECTIVE ACTION: THE LHIB BRAKE TEMP SENSOR WAS REPLACED. (TC# 20180618006)