The fluid should meet Allison TES-295 specifications.
My shop uses bp Autran Syn 295.
Be aware that there are deep and shallow transmission pans (you most likely have a deep pan, but who knows) and there are two different internal filters out there. A short filter in a deep pan will fall off, and cause a bunch of weird codes as the thing sucks in air.
There's a donut-shaped magnet that sits on top of the spin-on filter. This often is unnoticed and is thrown away during filter changes. Make sure the magnet exists.
If you drop the pan and change the internal filter and the spin-on filter, you'll need about three gallons of fluid.
If the ABS light is on, the torque converter will not go into lockup and it'll shift weird and then overheat. Fix any abs problems immediately.