As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT A 'DOOR PASSENGER FORWARD OPEN' MESSAGE WAS PRESENT ON THE EICAS SYSTEM DURING FLIGHT. IN FLIGHT INDICATORS WERE GREEN AND PRESSURIZATION WAS NORMAL. CREW LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE L1 DOOR ELECTRONIC INDICATOR CONNECTOR LOOSE. MAINTENANCE RE-SECURED CONNECTOR PER EMB AMM 52-72-2 AND OPS CHECKED GOOD.