If your vibe is not AWD, then the auto tranny is model A246E. rockauto.com says a TCC for an A246E tranny looks like
judging only by the look of the part, I'd say that its something inside the tranny, not directly accessible from the outside, but that's not a very authoritative answer.
Some other P0741 threads here are
Some in those say their P0741 was a loose connection, or fixed by a tranny fluid change
As I understand it, the TCC locks the torque converter so there is no slip between the engine and the transmission, and if it doesn't lock up, then you will get a little slip in the torque converter, which will drop your cruising MPGs a little.
It seems very unlikely that an issue with the TCC could damage the engine to the point of losing all compression. Seems more likely a blown head gasket, or oil pump failure, or even something like this was the cause:
Sorry to hear about the trouble.
This being your first post here, Welcome to genvibe!