As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) VERY SLOW TO SLAVE WHEN COLD SOAKED OVERNIGHT AT -20 DEGREES C. TOOK APPROXIMATELY 15 MINUTES TO ALIGN. AFTER ENGINE START, OPERATED OK DURING FOLLOWING FLIGHTS, UNTIL COLD SOAKED OVERNIGHT AGAIN WHEN VERY SLOW TO SLAVE. REPLACED DIRECTIONAL GYRO, GROUND CHECKED OK.