As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT, VIBRATION FROM NR 1 ENGINE WAS FELT THROUGHOUT THE AIRCRAFT ACCOMPANIED BY FLUCTUATIONS IN FUEL FLOW N1, AND THROTTLE POSITION ON ECAM INDICATION. POWER WAS REDUCED, BUT ENGINE PERFORMANCE WAS STILL ERRATIC. AIRCRAFT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. THE HMU WAS REPLACED AND POWER ASSURANCE CHECK PERFORMED AND THE AIRCRAFT WAS DEEMED OK FOR SERVICE.