As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING CLIMB #1 ENGINE EGT DISPLAYED "XX" - NO INDICATION OF EGT TEMPERATURE. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO DFW WHERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE ENGINE ELECTRONIC CONTROL, UNIT (EEC) PER AMM 73-22-34. (AALA202108236917) ALSO REPLACED ALL 4 EGT THERMOCOUPLES PER AMM 77-21-15. (AALA202108237446) A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.