Hello,
I am testing my XK8 which I recently restored. Today I drove for about 10 miles on smooth roads and everything went well, perfect engine and gearbox. Returning to my downhill village. Having to give priority to a rising vehicle, I had to stop and reverse for a few meters. Returning the gearbox to D to continue I heard a "clunk" then GEARBOX FAULT on the display and the car was no longer moving forward. Off and on again and everything worked. I therefore walked the streets of the village for a few more miles to see if there were still problems. All quiet. I then reproduced the same situation, reverse downhill: same result, clunk! I read the error P1722. Where do you think I start the diagnosis? Could it be the fault of a low level of the gearbox fluid?

 

One of the POSSIBLE CAUSES is LOW OIL LEVEL.
DTC guide for you.

 

yesterday I put the car on the lift and got ready for the refill. I opened the fill plug with the engine running and the oil sump which measured 35 degrees celsius. Surprisingly, half a glass of oil came out. Apparently there was too much oil ... I tried the Jag after this work and even replicating the descent experiment everything went well. The gearbox shifts smoothly in any situation. Do you think this is a coincidence or is it possible that that excess of oil caused that malfunction?

 

Just wanted at ask what code reader you used to read the fault, new to me STR with a transmission fault and my Delphi DS150e will not connect to the car.