As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO DEPARTURE DUE TO LT ENGINE FIRE WARNING. CREW ACCOMPLISHED QRH PROCEDURES. BOTH FIRE BOTTLES WERE UTILIZED AND FIRE WARNING REMAINED WITH ENGINE SHUTDOWN. MAINTENANCE REPORTED FIRE INDICATION ILLUMINATED AFTER ACFT ARRIVED AT THE GATE. DISCONNECTED LT ENGINE FIRE DETECTOR CONTROL UNIT AND FIRE INDICATION EXTINGUISHED. R & R FDCU AND ACCOMPLISHED CHECK OUTS IAW AMM. R & R BOTH FIRE BOTTLE ASSEMBLIES IAW AMM. C/W ENGINE IFSD CHECKOUTS IAW AMM.