"We fired up the truck and backed it out of the shop. After driving up and down the street, we realized we had a problem. The speedometer did not work. Due to this problem, the motor would go into a limp mode after driving a small distance. It would stay running, but would lose all power. It would take a few seconds to kick back in. We were prepared to see the anti-lock brake light, and the 4x4 light, but not this. While taking out the original axles, we did notice that there were 4 separate speed sensors; one at each wheel. We also noticed that there was a speed sensor in the tail shaft of the transmission. At that time, we did some research on the internet. We also talked to a few Nissan techs. Everyone came to the same conclusion. The wheel sensors were supposed to be for the brakes and the tail shaft sensor was supposed to be for the speedometer. I guess we concluded wrong. With such new technology, nobody really knew how it worked."
You should've done a search or started your own thread for this. Your tpms sensors are behind the valve stem inside the wheel. I'm guessing the battery has died in one or more, but you can try to search for "tpms reset procedures".....I don't have time to find it for you.
For anyone that cares or doesn't already know, the VSS is inside the tail housing of the transmission near the parking pawl.