As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CLIMB, PILOT NOTICED CABIN RATE OF CLIMB INCREASING AT +800 FT/MINUTE AND BY FL200 THE CABIN PRESS WARNING ANNUNCIATED. PILOT DECLARED MAYDAY AND ACTIONED AN EMERGENCY DESCENT AND DIVERTED TO BASE, MAYDAY WAS DOWNGRADED TO A PAN. AT FL100 WARNING LIGHT EXTINGUISHED. UNEVENTFUL LANDING MADE. ECU FAULT CODES, FAULT CODES IN THE ECS ECU, LT CHANNEL. ECS ECU REPLACED.