As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER TAKEOFF, UNABLE TO TRIM AIRCRAFT HORIZONTAL STABILIZER, AIRCRAFT RETURN TO OTTAWA, UNDER QRH PROCEDURE. RESET ATTEMPTED WITH NO SUCCESS. FOUND TO BE THE HORIZONTAL STAB TRIM CONTROL UNIT AT FAULT. REPLACED THE HORIZONTAL STAB TRIM CONTROL UNIT. OPERATIONAL AND FUNCTIONAL TEST CARRIED OUT AS PE TASK 27-40-00-710-801 AND 27-40-00-720-801 TESTED OK.