[vescano]

I'm the fleet mechanic for a taxi company using mostly xb's, and I'm running into a very similar issue.

Are you having issues shifting into fourth gear? With this kind of code it's telling you that the input speed sensor and the output speed sensor aren't agreeing with each other on how and when to shift.

What kind of scanner are you using? If it's just a cheap job from Auto Zone or something like that, then it's only going to give you soft codes, and not all possible codes. A more expensive one gets more into depth, but you need a Snap-On type scanner or the equivalent. If you have the type of scanner that will give you live transmission data, drive it with the scanner on it, and while it's moving check to see if the NC and NT speed sensor circuits are showing turbine RPM data. If either of them is showing zero (which I suspect your NC circuit will) then that's where you want to start.

If you don't have live data capability, you'll need to take it to someone who does.

I am having problems with shifting into 4th, it doesnt shift into it at all. Autozone gave me the same code (p0793). Was the sensor under the air box the one you replaced to fix this problem? where is the other sensor located?