As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOST DIRECTIONAL CONTROL WITH NOSE WHEEL STEERING AND RUDDER IMPUTS. ACFT VEERED HARD TO THE RT. NO CAUTION MESSAGE WAS RECEIVED, AFTER STOPPING, NOSE WHEEL STEERING WOULD NOT REENGAGE WITH SWITCH AND STEERING INOP CAUTION MESSAGE APPEARED. REPLACED HCU DUE TO FAILURE OF CALIBRATION CHECK OF STEERING IAW AMM. PN ON/OFF 16650-101, SN ON DCL884/02, SN OFF DCL871/02.