As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: DOOR LEFT AFT EMERGENCY EXIT ECAM AT FL 340. FLIGHT CREW REPORTED THAT PRESSURIZATION AND CABIN VS LOOKED NORMAL. REPLACED THE LEFT AFT EMERGENCY EXIT DOOR DETECTOR PROXIMITY SENSOR PER AMM 52-71-13 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.