Quick point about codes: because a code refers to something that's located in 'assembly X' does not always mean you should go buy assembly X and replace it. Sometimes it does, but sometimes the cause could be something simpler. Especially when assembly X is both expensive, and a bear to replace, it can definitely be worth looking the code up in the manual to see what its "detecting condition" is, and working through other possibilities for what could have caused that condition (the manual will have a suggested sequence of tests you can try in order to do so). At least that way, if you do end up at the conclusion that you need to buy a transaxle, you'll feel more confident you haven't overlooked something simpler. -Chap
There are a couple electrical connectors that go to the transaxle, maybe you can disconnect them and see if the error goes away (or there's a problem with the connectors themselves). The sensor is inside the transaxle and can't be replaced by itself