As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND FAULT CODE 77-20871 THE TOP LEFT EGT SIGNAL (T495S4) IS OUT OF RANGE FOR NR 1 ENGINE. ECONOMIC FAULT. ACFT GROUNDED. REMOVED AND REPLACED THE NR 1 ENGINE CJ10 HARNESS IAW AMM 73-21-06-400-803-F00 & FADEC SYSTEM TESTED GOOD IAW AMM 73-21-00-700-F00.