As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
YAW DAMPER ENGAGED ON TAKEOFF ROLL, CREW ABORTED TAKEOFF GOT AND YAW DAMPER/RUDDER BOOST FAIL ANNUN WHEN TAXIING. RETURNED TO GATE AND THE SYSTEM WAS DEFERRED WITH NO FURTHER INCIDENT. COULD NOT DUPLICATE ON GROUND YAW DAMPER OPS CK NORMAL.