As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FOLLOWING A SCHEDULED ENGINE CHANGE, ENG PRESS WARNING LIGHT CAME ON DURING A TEST FLIGHT. PILOT LANDED WITHOUT INCIDENT. SUBSEQUENT TROUBLESHOOTING REVEALED DISENGAGEMENT OF THE ENGINE OIL PUMP DRIVE ADAPTER FROM PUMP SLINES. DRIVE ADAPTER APPEARS TO HAVE LOST LOCKING FEATURE, HENCE THE DISENGAGEMENT. THE ENGINE ASSEMBLY TSR=0.3 HRS. (TC# 20091202017)