As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN APU FAULT MESSAGE, PLUS A STRONG BURNING ODOR, DURING LANDING ROLLOUT AT DCA. MAINTENANCE INSPECTED THE AIRCRAFT, REMOVED AND REPLACED THE APU AND PERFORMED CHECKS USING THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.