As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IND FLT1831 EN ROUTE FROM ORD TO CLT, THE NR 2 ENGINE CSD LOW OIL PRESSURE LIGHT ILLUMINATED. CREW DISCONNECTED THE NR 2 ENGINE CSD. CREW THEN STARTED THE APU BUT THE APU OVERSPEED LIGHT ILLUMINATED AND THE APU AUTOSHUTDOWN. FLIGHT DIVERTED TO IND AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REMOVED AND REPLACED APU CONTROL UNIT (M280 MODULE). OPERATIONAL CHECK GOOD. ALSO, REMOVED AND REPLACED THE NR 2 ENGINE CSD PER MM 24-11-11. OPERATIONAL CHECK AND LEAK CHECK GOOD.