As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AIRCRAFT EXPERIENCED RUDDER OSCILLATION AT 12,000 FEET. OSCILLATION STOPPED DURING DESCENT AT 165 KNOTS. PROBLEM TRACED TO YAW DAMPER SYSTEM. YAW DAMPER ACTUATOR SECONDARY COIL FOUND OPEN IN LVDT UNIT THAT IS INTEGRAL TO ACTUATOR. PART TC: 43,122.