As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. EMERGENCY DECLARED. IND-DFW FLIGHT RETURNED TO DFW ACCOUNT UNABLE TO PRESSURIZE CABIN. OVERWEIGHT LANDING UNEVENTFUL. REMOVED AND REPLACED CABIN PRESSURE CONTROLLER NR 1(AALA20170204005) AND CABIN PRESSURE CONTROLLER NR 2 IAW AMM 21-32-03. LEAK AND OPERATIONAL CHECK GOOD.