Recently, I have been experiencing problems with my MTH engines and it seems it is a TIU problem. I started looking for a new one and have found there are none available. In a discussion with a larger MTH dealer, he indicated that they are expecting delivery of WIFI modules in the next several months but no TIU's. So I guess if I refuse to go the WIFI route, I am out of luck and might as well sell my MTH engines. I purchased a second hand held remote never considering I should have gotten a new TIU last year when they were available.
I guess you might say a I am very frustrated!