TIMS showed Smoke External Alarm at car1526 Staff(AMK) checked and confirmed no signs of smoke / fi re / burning smell on exterior or interior of train. Rear T2 13line clear and confirmed no abnormalities. TIMS showed Smo ~~~~~ TIMS showed Smoke External Alarm at car   Found smoke detector unit to be dusty. Replaced, installed with cable gland and plaseal. Conducted function test ok. Notification to CSC: 2569356 Done by: Martin, Sufhian, Rudy (8/2/24)