As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NOSE GEAR DOWN PROXIMITY SWITCH NOT GIVING DOWN AND LOCKED INDICATIONS ON NOSE GEAR. REOCCURRING PROBLEM AROUND THE 9000-10000 CYCLE RANGE ON PC-12'S. PC-12'S INCORPORATE THESE SWITCHES IN THE NOSE GEAR UP AND DOWN LOCK INDICATION POSITIONS THE MAIN GEAR UPLOCK POSITIONS AND THE MAIN GEAR WEIGHT ON WHEEL POSITIONS.