As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING CIDS BITE TEST: ESCAPE SLIDE LIGHT/EMERGENCY POWER SUPPLY UNIT (15WL) MID LEFT MESSAGE DISPLAYED. MAINTENANCE ACCOMPLISHED TSM 25-62-00-810-815A AND REPLACED THE 2L DOOR SLIDE PER TASK CARD 26L00025012. A SATISFACTORY OPERATIONAL CHECK OF THE EMERGENCY LIGHTING SYSTEM WAS ACCOMPLISHED.