As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STEERING INOPERATIVE CAUTION AFTER PUSHBACK. RAN QRH MESSAGE CLEARED. (FLIGHT 4710) INTERROGATED MDC AND FOUND FAULT CODE B-007456 FOR NWS ECU FAILED DUE TO INTERNAL FAULT. REMOVED AND REPLACED NWS STEERING ECU REFERENCING APPLICABLE STEPS OF AMM 32-51-10. RIG CHECKS GOOD. PERFORMED MULTIPLE OP CHECKS OF NWS DURING GROUND TAXI RUNS WITH NO ISSUES NOTED, COULD NOT REPEAT STEERING INOP CAUTION MESSAGE.