As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IOP 2 FAIL INDICATED IN CLIMB. AIRCRAFT RETURNED TO THE POINT OF DEPARTURE. MAINTENANCE CARRIED OUT IOP 2 SYSTEM TEST AND NO FAULTS FOUND. SYSTEM TESTED SERVICEABLE. IOP 1 AND 2 SWAPPED FOR TROUBLESHOOTING AND TESTED SERVICEABLE. 5 FLIGHT HOURS LATER (4 CYCLES) IOP 1 FAIL MESSAGE APPEARED ON LANDING. IOP 1 WAS REPLACED BY MAINTENANCE.