From Yahoo answers:

OK This just absolutely drives me insane. People that don't know what they are talking about giving advice. P0700 EATX CONTROLLER FAULT PRESENT. Means that the PCM sees a fault code stored in the TCM. NOT THE TCM IS BAD. I don't know how many times I have told people on here about that but people keep saying it. You have a fault code stored in the transmission control module. You need to find a scanner and read what that code is. There could be several things that could be the problem and none of them are the TCM. The Trans controller cannot turn on the check engine lamp by itself so it sends a bussed message over the PCI bus to the PCM. The PCM sees the request and puts up the P0700 code to alert you to check the TCM for stored diagnostic codes. Could the TCM be bad anyhow? Yes but that is not what that code is saying. I wish people would read and learn a little before spouting out about what they don't know. Bad advice is worse than no advice. You could have spent 300 or more on a TCM that won't fix your problem. Sorry about the rant but it really chaps my a$$.