As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED, -DU4 OVERHEAT- MESSAGE DISPLAYED FOR ONE SECOND THEN CLEARED. ABOUT 30 MINUTES LATER DU4 WENT BLANK FOLLOWED QUICKLY BY INTENSE, ACRID ELECTRICAL FUMES. DECLARED EMERGENCY AND DIVERTED TO MEM, AIRCRAFT LANDED UNEVENTFULLY. MAINTENANCE REMOVED AND REPLACED THE NR 4 DU-870 IAW EMB145MM 34-22-01. OPS CHECKED GOOD. NO FUMES NOTED. AIRCRAFT RETURNED TO SERVICE.