I think I finally found the info I need here. No one seems to have the P0743 code in many MB forums. I hope someone here can help me.
My 2000 CLK430 recently ran on limp mode with CEL on and 2 error codes (P0720, P0743). I did lots of research online and found the problem were the electric plate on the valve body and solenoid Y3/6y6 (torque convertor lock up). I changed the 2 parts(the plate and the solenoid) and went to MB dealer and reset the CEL. My car ran fine for about 300 miles.
Then yesterday, the limp mode hit once again w/o CEL but the DTC code P0743 came back. (Car is normal now but have that DTC code) What should I do now? I want to pull the trans computer to check if oil made it up there because the connector was leaking. Where is the trans computer?
Hello, your problem is most likely not the transmission computer. your first code PO720 was the contactor plate "speed sensor n3", you fix this. The second code is "PO743 Torque converter electric circuit fault". You need to check your torque converter solenoid or you have a bad connection, between solenoid and the conductor plate, after assembly the conductor plate,-this habens many times. This is the first solenoid on the side where only two solenoids located. If you still have problems and not locate or fix the failure check if your failure is permanent or sporadic.
When you reset the computer,clear all fault codes, see if transmission reset and like to drive normal for a wile, or the code comes back after clearing all codes and before you driving the car?
