Reading engine codes doesn't mean that you will find the TRUE trans problem. YOU need to have transmission codes read from the trans!

PO 743 means the trans torque-converter lock-up isn't working properly (electrically).

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

When I replaced the conductor plate, I accidently bend one of the tabs on the 3/6y6 solenoid. That caused the PO743 code. I replaced the solenoid and had my friend at the dealer clear the ETC of all codes and everything is working fine. It is really important to have those codes cleared from the transmission computer as it will remain in limp mode until you do.