As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE FROM DAY, THE CREW RECEIVED A LEFT HAND EMERGENCY DOOR OPEN INDICATION. FLIGHT 9412 THEN RETURNED TO DAY. MAINTENANCE INSPECTED AND ADJUSTED THE EMERGENCY DOOR PROXIMITY SENSOR IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 52-00-00. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.