Was just another routine start for a short haul for some little piddly stuff to be worked on here in Bend. Shifted into "D" and began to roll. Then Red "Check Trans" dash light came on. I looked at Allison sifter readout expecting to see the normal 6 1 meaning 6th was the highest possible gear and 1 was the current gear. 1, on the right side where you'd expect it was illuminated but not the normal 6. And furthermore the transmission was completely frozen in that state, in first gear. I sat there and called the Allison facility in Redmond, Oregon who said, "have the rig towed to us" Well nuts! I remembered a T shirt I saw once that said, "If I'm ever on life support, unplug me. Then plug me back in. See if that works." So, I gave it a try and turned off the ignition. I waited about a minute and fired her back up. All systems nominal. I drove to the shop in Bend where I was originally destined and the guy said, "Ya, they do that now and then. Just shut it down and then restart. Usually straightens things out." Naturally, I liked that report better than Tow it to us. Anybody had a similar experience with an Allison 6 speed? (I gotta buy that shirt)