As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ON FLIGHT NUMBER 2354, NOSE WHEEL STEERING CAUTION CAME ON 8 SECONDS AFTER NOSE WHEEL STEERING SELECTED ON. CONDUCTED ABNORMAL CHECKLIST PROCEDURES AND CAUTION RE-ILLUMINATED. INTERROGATED SCU CODES. CLEANED SCU AND FOUND SQVC TO BE HARD FAULTED. REMOVED AND REPLACED NOSE WHEEL STEERING MANIFOLD. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.