Auto shift maybe splitter prob?
01 columbia C12 RTO 16710C-A82. smart shift
On,wed it stuck in 6th while downshifting. Turn truck off let it reset fiddeled with shifter got it working. No prob rest of day. Thrs started oit ok then same thing. Gets "F" on gear indicator for fault. Found that on downshifting if I let it get to 6th then push clutch in wait for 5th keeps going down ok. On up shift now gets fault going fron 5th to 6th but keeps up shifting ok while flashing "F" Drive for a while in 10th fault goes away. When stuck in 6th an shift to N doesn't go back into D will go reverse but it is R2 "hi side" shift to L goes to 6th.
Limping along until home fri tjen to shop. Hope it's a sensor not not $$$$$
Is this a good question?