Code 1698 speedometer does not work, what to check?

Question

Speedometer does not work, not shifting stays in 1st gear. Get a code P1698 Has a new battery, New output sensor. The car has sat for over a year, was fine before it was parked. Had same problem 8 years ago, mechanic said it was a wire that time.
What should I check?
Looked at wires and grounds and see no issues. Have had mice cause problems on other vehicles

Answer 1

P1698 No BUS message from transmission control module

Open wires or chewed out wire is what you would have to look for. this can be tied in the wiring harness. The best way to do this  is using a factory level scan tool with transmission data and wiggling the wire looking for any change in the data stream for the transmission data