As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) NR 1 ENG OIL PRESS WARNING LIGHT ILLUMINATION IN FLIGHT, ENGINE SHUTDOWN IN ACCORDANCE WITH QRH/AFM, AIRCRAFT RETURNED TO DEPARTURE AIRPORT AND LANDED SAFELY. MAINTENANCE DETERMINED NR 1 OIL PRESSURE SWITCH FAILED. SWITCH REMOVED AND REPLACED. ENGINE RUNS CARRIED OUT, OPERATION SATISFACTORY. AIRCRAFT RETURNED TO SERVICE. SWITCH MANUFACTURER (CUSTOM CONTROL SENSORS) NOT IN THE DROP DOWN LIST.