As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - DURING MAINTENANCE INSPECTION, THE AFT EMERGENCY LIGHT WAS FOUND TO BE INOPERATIVE. MAINTENANCE REMOVED AND REPLACED THE NUMBER FOUR EMERGENCY LIGHT BATTERY PACK, OPERATIONALLY CHECKED WITH NO DEFECTS NOTED, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.