As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 336 - DURING CRUISE, THE NR 2 CSD LOW OIL PRESSURE LIGHT ILLUMINATED. THE APU WAS ON MEL AT THE TIME. THE ACFT RETURNED TO THE FIELD AND LANDED WITHOUT INCIDENT. MAINTNANCE FOUND THE NR 2 CSD OIL OVERSERVICED. THE OIL WAS DRAINED TO THE CORRECT LEVEL AND THE MAG PLUS CHECKED. OPERATION WAS NORMAL DURING TEST. (X)