As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: CIDS MESSAGE AFT LEFT EMERGENCY POWER SUPPLY UNIT INTERNAL LOAD FAULT. REPLACED AFT LEFT (L2 DOOR) SLIDE AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK OF THE EMERGENCY LIGHTING SYSTEM WITH NO FAULTS NOTED ON THE CIDS.