You won't pass inspection with it like that (if that's a concern), monitors have to be ready and never will be if you keep cycling power. Where did you see something relating to ECTS? And by that, is you mean the coolant temp sensor? Quick search on the code brought up stay alive power voltage too low, which would suggest too much resistance in the wire feeding power to your ECU, bad fuse etc. If you haven't already, subscribe to Toyota's TIS site for a day and download all the wiring for your truck, will be able to pinpoint this and more that way. Would think you'd have no trouble finding an ECU on ebay, just pull and match part #, but if you have a 3.4 with 5 spd trans it'll cost you. Auto trans ECU should be cheap. But if it's a wiring issue a new ECU won't fix it