Rialta TCM's are not made anymore but here is a TN company that may can repair yours. Here is a reply from them to me about TCM's.
http://www.autoecu.com/
I own a 2004 Winnebago Rialta with the VW 24valve V6 engine. If my TCM goes out, can you rebuild it? New TCM's are not made anymore and there is a large group of Rialta owners that may need this service if their TCM's go out. The TCM was programed for different shift points because of the larger weight of the R vs. the Eurovan. Also the early 96-2001 TCM's have a different part # than the later models and can these be rebuilt? System Technical Department 2. Hello, We can test the unit. Our test fee is $55. If we locate issue with the unit, then we will contact you with a rebuild cost on it prior to repairing it, so that you can either agree to the cost or decide not to. Please send in to us and allow 2 business days to test. Please send to us along with our R&R Form, copy and paste the following in your web broswer, and print off and fill out. Include it with the part when sending it in. Thank you