2003 deville service engine light

The service engine light stays on when car is started-won't go off. I have taken it to dealership, and was told it was the torque converter. They want $3500.00 to repair it. Is there anything else I can do to make sure that this is the problem? The car runs fine.It shifts like it always has, and only has 30,000 miles on it. I think the dealership is trying to rip me off. scn code was DTC po741

Auto zone can look it up for free (the code) they say it is a trans code for a electrical solonoid failure (in the trans). Ask autozone to reset it or do it yourself ( hold info and the on/off swiches down concurrently, key switch on, do not start car, on top right part of dash) you should see the whole dash illumination change, use on/off button to run thru all codes and at the end it asks for----" do you want reset all codes?" hit it again and it'll reset the whole works to zero codes. If the po 741 does not come back it is a fluke. there are many flukes like this, if it come back over and over it is a trans problem. It may be servicable by just taking the trans pan down and not pulling the whole thing. need to ask a trans guy on that point