As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED, RECEIVED AN APU OIL PRESSURE MESSAGE IN FLIGHT. BECAUSE THE RIGHT IDG WAS DEFERRED THE CREW DIVERTED TO BHM LANDING WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT THE APU OIL SYSTEM USING THE AIRCRAFT MAINTENANCE MANUALS. THE LOW OIL PRESSURE SWITCH WAS REMOVED AND REPLACED. CHECKS WERE MADE USING THE AIRCRAFT MAINTENANCE MANUALS AND AIRCRAFT WAS RELEASED FOR SERVICE.