As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE, THE CREW RECEIVED A OPEN DOOR INDICATION ON THE RED WARNING PANEL FOR THE PASSENGER DOOR. THERE WAS NO LOSS OF PRESSURE AND THE DOOR WAS SECURE. FLIGHT 4195 THEN DIVERTED TO PIT. MAINTENANCE INSPECTED AND REPLACED THE 8MC OVER THE CENTER PROXIMITY SWITCH IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 52-00-00. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.