As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT AFTER NORMAL TAKEOFF, THE YAW DAMPER AND AUTOPILOT FAILED TO ENGAGE ON SEVERAL ATTEMPTS. AIRCRAFT THEN DIVERTED TO DAL. MAINTENANCE CLEANED THE CONTACTS AT THE YAW RATE SENSOR AND APS-65. GROUND CHECK WAS GOOD. AIRCRAFT RETURNED TO SERVICE.