TC reported 'Smoke External' present atrear M2 car. Staff(EUN) checked and feedback no signs of smo ke or heat on interior and exterior of train. Rear T347 perf ormed line clear in ATPM and confirmed there were no abnorma ~~~~~ #2516 SMOKE DETECTOR ALARM.CHECK CONFIRM FAULT AT #2516.FURTHER CHECK FOUND #2516 SMOKE DETECTOR EXTER L WATER INGRESS.C/O DONE OK.USING PLASEAL TO SEAL THE CABLE GLAND.SECURE/FUNCTION CHECK DONE OK. JIA WEI/HAFIZ/SHAHRIE 26.01.2023