As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PRESSURE CONTROLLER FAILED ON CLIMB OUT FROM YYC. A/C RETURNED TO YYC. O2 MASKS DEPLOYED. CABIN PRESSURE CONTROLLER FAILED FUNCTION TEST ON GROUND. REPLACED O2 MASKS AND REPLACED PRESSURE CONTROLLER. FUNCTION CHECK CARRIED OUT AND A/C RETURNED TO SERVICE.