Originally Posted by dwaugh10
Brand new Tiffin RED340. Noticed that when I first turn the key to the "on" position before starting engine, the Allison keypad says: "TCM Communication Fail" and then clears in a couple of seconds. This is an Allison 2500MH.
Is this normal?
No, it's not normal. Comm errors are usually related to a connector that is corroded or worked loose. Since your's is new, I would not suspect corrosion. Check all of the connectors on the transmission and the engine or take it to a service center.