As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE ANTI-ICE TURNS ON IN AUTO MODE EVEN WHEN THERE IS NO VISUAL INDICATION OF ICE, NOR SAY ICING CONDITION. SUSPECTED ICE DETECTION SYSTEM INTERMITTENTLY AT FAULT. DDG 30-80-01-02 PO APPLY FOR ICE DETECTION SYSTEM PRIMARY INOPERATIVE.