As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT DIVERTED TO DFW. FLIGHT CREW REPORTED THAT AT CRUISE ALTITUDE OF 32,000 FEET, CABIN PRESSURE VERTICAL SPEED CONTINUOUSLY FLUCTUATED +/- 250 UP AND DOWN AND OUTFLOW VALVE CONTINUOUSLY WAS OPENING AND CLOSING. ALL ENGINE PARAMETERS AND BLEED PRESSURES WERE STABLE. THE AIRCRAFT LANDED SAFELY AT DFW WITHOUT FURTHER INCIDENT AND TAXIED TO THE GATE. MAINTENANCE REPLACED THE #1 ENGINE STARTER AIR VALVE AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.