2014 Kenworth T800 vehicle Speed not reading

Good evening everyone,
New to the forum hopefully I'm posting in the right place, looking to get some help with electrical issues were having on a customer's truck, there's a ton of issues currently some we've got figured out but might still be worth noting for the current troubles, we had a regen issue which ended up being a loose fuse connector in the engine fuse box we have the aftertreatment circuit rerouted to a spare fuse location for the time being while we wait for parts the ongoing issue is the rpms are currently limited do to a missing vehicle speed signal, the tail shaft speed sensor was replaced and we traced and ohm'd the wiring back to the computer and all test out ok, we back probed the pins for the speed sensor and got a reading of 9 volts coming out of the computer checked in Mitchell and can't find a value for this not sure if it should be getting 12 volts or a 5 volt reference but pretty confident 9 volts is no good were also not getting a reading on the trans temp sensor from what we see all the wiring appears to be ok starting to suspect a computer issue any help is greatly appreciated before we move ahead with a computer.
looking forward to being a part of the forum and contribute where possible, thanks in advance.
Chris