TIMS showed Smoke Internal at car 3505.Staff(CTH) checked and confirmed no signs of smoke / fire / burning smell on exterior or interior of train. Train was es corted to terminal station. TIMS showed Smoke Internal at ca ~~~~~ TIMS showed Smoke Internal at car 3505.   Fault unable to duplicate in depot. Cleaned 3505 internal smoke detector. Checked control panel and found no water ingressed. Monitored for an hour with no fault triggered. N.AZAIDI/IDRIS/12.09.23