2005 Freightliner M2 Allison w/ Cat C7 - Tranny acting up

Good Evening everyone. Got a great truck here that is acting up. Transmission wont shift out of first gear and check engine light blinks. occasionaly dash says "no trans". Was recently checked out by the local Allison shop and they said it wasn't throwing any codes. Problem has been intermittent but has recently hit wide open, causing trouble 24/7.

Bad ground?
Bad Fuse?

seems like a electrical issue. clutch test at allison went well.

Looking for direction here. Thank you in advance.

2005 Freightliner M2 Allison w/ Cat C7 - Tranny acting up