Train encounter obstacle detector at Front M1 'A2' door when train departing YWT. TC feedback no abn ormalities at KRJ. Fault self-cleared. Train encounter obsta cle detector at Front M1 'A2' door when train departing YWT. ~~~~~ 1611 encounter obstacle detector at A2 door when departing YWT. TC feedback no abnormalities at KRJ. Fault self-cleared. Train encounter obstacle detector at Front M1 'A2' door when train departing YWT.  1611 Checked no door fault FC. Checked door weather strip & roller conditions ok. No FOD on door guide. Cleaned J rail as preventive measure. Swop DCP from #1611 A2 to #1611 B2 for monitoring.  Daniel/Redzwan/Chan SW 45348 DCP S/N : #1611 A2 : 1411W020021S036 #1611 B2 : 1411W020021S035