TIMS showed Smoke External Alarm at car3512 Staff(WDL) checked and confirmed no signs of smoke, bur ning smell on exterior or interior of train. Rear T204 line clear and confirmed no abnormalities. TIMS showed Smoke Exte ~~~~~ 3512 TIMS showed Smoke External Alarm. Staff(WDL) confirmed no signs of smoke, burning smell on exterior or interior of train.    Rear T204 line clear and confirmed no abnormalities. CE : 3512 smoke external alarm able to reset. No abnormality.  3512 FC 721 (smoke external) but Resettable. Swap SDR11 from #3512 to #1512. OPS 20 raised to check on Exteranl smoke detector.  Aliff/Daniel/Redzwan 45468 BSD/TWD: 3512 To Check External Smoke detector   Checked and found #3512 external smoke detector sensor cracked. Replaced with serviceable spare. Function test ok. Notification to CSC: 2613735 Done by: Sanip, Koh, Rizman (3/7/24)