2005 Toyota Corolla • 125,000 miles

Hi there my obd2 scanner says po741 on my 2005 toyota corolla with 124k miles. I have been reading so many conflicting answers about what the problem could be or the symptoms it should show or not show. For example the car runs fine and I do not notice anything wrong while driving or shifting.
I have also read and heard from a smog mechanic that there could be a problem with the ecu throwing a wrong code which was a problem with that year. Although I have read that other ppl have had there ecu replaced with the same code popping up and other ppl changing the solenoid with the problem still showing up. Ive been told the torque converter solenoid is in the transmission fluid pan and if thats the case how do I check to see if its working with my voltmeter? Any suggestions? I would like to do the job myself and replace the solenoid it thats the problem. But I still dont know how to go about making sure its the solenoid rather than the ECU. I am stuck cause I dont want to take it in and pay 125$ for a mechanic to say something I may already know.
Thank you.
June 21, 2013.

- Low transmission fluid level
- Dirty transmission fluid
- Faulty torque converter clutch solenoid valve
- Torque converter clutch solenoid valve harness or connectors
- Torque converter clutch solenoid valve circuit is open or shorted
- Transmission internal mechanical problem

The torque converter clutch solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Lock-up piston operation will then be controlled. When the torque converter clutch solenoid valve is activated, the torque converter lockup clutch will engage creating a 1 to 1 RPM ratio between the transmission input shaft and the rotational speed of the torque converter.

Lock-up operation, however, is prohibited when A/T fluid temperature is too low.

When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.

Jun 21, 2013.
Hey there thank you for your response, I just bought the car and after a 2nd look at the transmission fluid I see that it is. BLACK.I will do a change and see what happens. Thanks again!

Jun 22, 2013.
Ok, re post how it goes after that.

Jun 22, 2013.
Hey there so I am having no luck getting this code to stop showing up. (P0741) faulty torque converter
I have changed the transmission fluid 3 times now until the fluid got back to its normal red color. I changed the filter and used brake cleaner to clean out the inside of the transmission to get the rest of the black oil out.
90 dollars later in transmission fluid and still no luck. I don't know what to do. I think I see the torque converter sensor in there but cant seem to find any pictures of the location on line.

I did find something in there that is about 3 inch long on the inside of the transmission front. Its silver and has a cylinder shape. It wiggles just a little bit and I cant seem to see how it would come out or how it would be tightened. This may be normal as well but I don't know if that's it or not. Hope this helps.

2005 toyota Corolla user.

Aug 8, 2013.
I will see if I can find a pic of the TTC lock up solenoid.

Aug 10, 2013.