From the Ross Tech wiki
http://wiki.ross-tech.com/wiki/index.php/17125/P0741/00185717125/P0741/001857 - Torque Converter Clutch: Stuck OFF / No Power being transferred
Possible Causes
Automatic Transmission Fluid (ATF) Level not OK Transmission Sealing faulty
Automatic Transmission Fluid (ATF) dirty
Torque Converter faulty or incorrect Torque Converter installed
Solenoid Valve 7 (N94)/Pressure Regulating Valve 4 (N218) faulty
Torque Converter Pressure Valve faulty
Valve for Torque Converter Clutch faulty
Torque Converter Lock-Up Clutch faulty/worn our
Possible Solutions
Check Automatic Transmission Fluid (ATF) Level Check Transmission Sealing
Check Automatic Transmission Fluid (ATF)
Check Torque Converter
Check Solenoid Valve 7 (N94)/Pressure Regulating Valve 4 (N218)
Check Torque Converter Pressure Valve
Check Valve for Torque Converter Clutch
Check Torque Converter Lock-Up Clutch
Have you actually tried to diagnose what the exact problem is?