What was found
IN DESCENT NR 1 ENG FADEC CAUTION AND POWERPLANT MESSAGE ILLUMINATED. RETURNED TO FIELD. LANDING UNEVENTFUL. FOUND FAULT CODE 912 ON NR 1 ENGINE, CH A & B. CLEARED IAW AMM TASK 73-21-00-070-801 & 61-20-36-070-801. REPLACED NR 1 FADEC AS A PRECAUTIONARY MEASURE IAW AMM TASK 73-212-01-000-801 & 73-21-01-400-801. NO FAULTS OR CAUTIONS. PERFORMED A GROUND IDLE RUN IAW AMM TASK 71-00-00-868-811 TWICE. NO FADEC CAUTION OR POWERPLAND MESSAGE. FOUND FAULT CODE 736 ON CH B NR 1 ENGINE. NR 1 FADEC CAUTION OR POWERPLANT MSG NEVER ILLUMINATED. RETURNED TO SERVICE.