As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX-NOSE WHEEL STEERING WARNING LIGHT CAME ON 3 TIMES DURING TAXI. STEERING DID NOT WORK. CYCLED STEERING SWITCH PER CHECKLIST. INSPECTED NOSE LANDING GEAR STEERING HARNESS. FOUND THAT WHEN HARNESS SUBJECTED TO VIBRATION, CAUTION LIGHT ILLUMINATED. REPLACED NOSE LANDING GEAR STEERING HARNESS. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.