What was found
A LEFT HAND PROPELLER LOW OIL PRESSURE WARNING MESSAGE ILLUMINATED, DURING THE TAXI PRIOR TO TAKEOFF. THE AIRCRAFT RETURNED TO THE GATE. PSA MAINTENANCE WAS DISPATCHED FROM PIT TO REPAIR THE AIRCRAFT. MAINTENANCE INSPECTED AND REPLACED THE LEFT HAND PROPELLER OIL PRESSURE SWITCH, IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 61-21-12. OPERATIONAL CHECKS AND LEAK WERE COMPLETED, AND THE AIRCRAFT WAS RETURNED TO SERVICE.