TIMS showed Smoke External Alarm at car2559. Staff(AMK) checked and confirmed no signs of smoke / f ire / burning smell on exterior or interior of train. Rear T 218 line clear and confirmed no abnormalities. ~~~~~ TIMS showed Smoke External Alarm at car     FC-721,Smoke external fault.Smoke test no function.Replace FSD and smoke test ok. Done by Sufian/Shah/Lingke.  15/08/23