As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI, THE CREW RECEIVED AN INTERMITTENT CARGO FIRE CAS MESSAGE AND FIRE WARNING ON THE RED WARNING PANEL. FLIGHT 4019 RETURNED TO THE GATE. MAINTENANCE INSPECTED AND FOUND A CHAFED WIRE. MAINTENANCE REPAIRED THE CHAFED WIRE IN ACCORDANCE WITH 26-00-00. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.