While coming back from a small vacation the trans started doing what it was doing when I bought the car. The slip and slow 1st gear engagement, followed by a SLAM into gear and a Transmission Fault error. I replaced the top and bottom half of the trans valve body with new parts. The top half had a passage split open, and the bottom half pressure valve was probably worn so I replaced the entire piece and installed the Transgo upgrade to boot. After that the trans shifted like a new car and there were no further issues until last Thursday. So, the better part of a year, but probably only a couple of thousand miles. Today I checked just in case the electrical connector had somehow worked loose with the washboard roads in that part of Mexico, but it was snug. Perhaps the trans was damaged worse than I thought and the A drum was hanging on by a thread?

This time it shows P1722 Stall Speed. Google provides nothing definitive. Does anybody know anything about this code?

I am looking at a 61K mile trans from a 1999 XK8 as a drop-in replacement. Also, I've chased down all the parts necessary to rebuild this one if that's a better option.

Any advice?

Thanks!!

 

I see that this thread is almost two months old. Did you ever get this resolved?

 

Sigh. Not yet. Lift time at the shop has become very scarce. I hope to start on this by the end of the month.

I opted for the replacement trans in order to speed up the process a bit. The parts for a rebuild came out to approximately the same as this low-mileage unit I purchased, about $700usd, so I opted for the somewhat faster turnaround and less time tying up a lift.