As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GROUND RAN THE AIRCRAFT AND NOTED THE LEFT ENGINE PROP GOVERNOR WAS FAILING TO CYCLE. THE ENGINE DATA WAS READ, AND THE INFORMATION SHOW THE GOVERNOR WAS JAMMED. THE PROPELLER GOVERNOR P/N: P-877-16, S/N: 15G365-H/G WAS REPLACED WITH GOVERNOR P/N: P-877-16, S/N: 16G101-I/G IN ACCORDANCE WITH THE DIAMOND DA-42NG MAINTENANCE MANUAL CH: 61-20-00. FOLLOWING A POST MAINTENANCE GROUND RUN AND LEAK TEST. NO ADDITIONAL DEFECTS WERE NOTED. THE AIRCRAFT HAS BEEN APPROVED FOR RETURN TO SERVICE.