As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN APU OIL TEMP AMBER MESSAGE DURING CRUISE EN ROUTE FROM CLT TO XNA. AIRCRAFT DIVERTED TO BNA BECAUSE THE RT ENGINE INTEGRATED DRIVE GENERATOR (IDG) WAS ALREADY DEFERRED. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE SERVICED THE APU OIL LEVEL AND PERFORMED CHECKS USING THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.