As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DOOR L3 INDICATES CHECK SLIDE PRESSURE. MAINTENANCE REPLACED THE DECODER / ENCODER UNIT B 300RH6 (DEU) AS A PRECAUTIONARY MEASURE PER AMM 23-73-47. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO FAULTS NOTED.