As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
YYC - ON FLIGHT 4345 (YYC-DEN) DURING CLIMB RECEIVED A DCU 1 STATUS MESSAGE. RETURNED TO THE FIELD AND ACCOMPLISHED A UNEVENTFUL LANDING. MAINTENANCE COMPLIED WITH FIM TASK 31-41-00-810-804-A01. NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.