As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EWR---CO4141, CREW REPORTED APU FAILED INFLIGHT (ON APPROACH). ELECTRICAL ODOR IN COCKPIT ASSOCIATED WITH THE FAILURE. MAINTENANCE INSPECTED AIRCRAFT AND DETERMINED APU FAULTY, AIRCRAFT PLACED ON MEL 49-00-00 CONTROL 013729. APU REMOVED AND REPLACED. MEL CLEARED AIRCRAFT RETURNED TO SERVICE.