EC135 Captain reported a Full Authority Digital Electronic Control failure on number 2 engine during descent. Captain diverted and landed uneventfully.

Narrative

Approximately one minute to the north from landing at ZZZ1; I scanned the instruments in preparation for calling the prelanding checklist. I detected Engine 2 FADEC (Full Authority Digital Electronic Control) failure with related caution lights. (Indicated were FADEC FAILURE; FLI (First limit Indicator) DEGRADE on the right and DEGRADE on the left side of the CPDS (Central Panel Display System). I advised the medical crew and notified Company of our condition; diversion plan to ZZZ and the need for a ground ambulance for our patient. I called ZZZ Tower; [requested priority handling] and needed an immediate landing on Taxiway 1 into the west/southwest wind.I identified and managed Engine 2 N1 to 80% plus/minus 2% with the number 2 throttle and planned a shallow approach to Taxiway 1. I advised the crew of the recovery plan; called the prelanding checklist and described what it would feel like to run onto a known; smooth; hard surface; which was accomplished unremarkably. Upon completion of the running landing; a normal shutdown was performed; whereafter the patient was transferred to a waiting ambulance for ground transport to Hospital. Company MedEvac maintainers immediately responded to the aircraft with ground handling wheels and a tug to clear the taxiway. ZZZ Fire/Rescue also responded to the aircraft but departed soon thereafter.I reported down and secure via radio to Company. Upon exiting the aircraft; I checked on the crew and patient who were already in the process of transferring the patient to the ambulance. I updated the Company by phone and notified Person A; Person B; by voice message and Person C by phone. Once the medical crew returned to ZZZ; we swapped into Aircraft Y for service and returned to base. Finally; we conducted a formal debrief of the [events] where I asked for questions and concerns. I advised both crew members to notify the on-duty contact if either felt the need to debrief the event emotionally or the need for further follow up of any kind.