As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - AFTER LANDING, THE GEAR HORN SOUNDED, AND THE LEFT MAIN GEAR INDICATED UNSAFE AND GEAR INTRANSIT. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND PSEU FAULT CODE AND A DISCONNECTED CANNON PLUG ON THE LEFT GEAR. THE CANNON PLUG WAS RECONNECTED AND A GEAR FUNCTIONAL CHECK WAS PERFORMED. CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.