gear

My transmission not going into 4th gear, check light comes on when reaches about 3000rpm in third. Whats the issue n does it ave anything to do with the ECU? i ave a 4efe 2nd gen. coil pack engine. Pls Help :( n oh tell me about the diff bearing in terms of the axle i hear a noise rumbling.

Dear Friends, Can anyone help me, how to recognize LSD gear , as i have starlet EP-82 with automatic transmission and wanted to change it into manual, the gears are available here, but they seller dosen't know anything about LSD, nor i know. Could you please help me? Aamir From Pakistan