As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MADE AN UNPLANNED STOP AT DEN DUE TO AUTOPILOT PROBLEM. CREW COMMENTS: UNABLE TO ENGAGE AUTOPILOT L-C-R, L AND C AUTOPILOTS CMD SW GIVES HORN AND LT WARN, R CDM SW NOTHING. THE DISCREPANCY IS ATTRIBUTED TO A MALFUNCTIONING FLIGHT CONTROL COMPUTER. REPLACED FLIGHT CONTROL COMPUTER. UA MAINTENANCE WILL BE MONITORING THE RELIABILITY OF FCC.