I was parked at the side of the street but wanted to go in the opposing direction.
I pulled out to do a 3 point turn. When I went to put the car in reverse the gear selector
knob was stuck. There was no way to put it in reverse and I was now blocking traffic. I had to drive up the sidewalk to turn around and then continued home.
I checked things over at home but eventually had to turn off the car. I tried disconnecting the battery and reconnecting it, hoping
it would reset itself to no avail. I had a mechanic come out who couldn't fix it either. I researched this on YouTube and people have had a similar problem
but normally it seems more common to get it stuck in park. I contacted the local Jag dealer and he had also heard of this before. With the long weekend the dealer was too busy to look at it for some time. The car has not had a proper diagnostic but I ordered a new gearbox unit anyway. It is supposed to arrive in Toronto today and then it will be shipped to me. The car has been in my driveway since last Thursday. I presently have 3 mechanics trying to help me out here but none are specific Jaguar mechanics. One of my concerns is if the transmission is actually in Park or Drive at this point. The shifter is stuck in Drive.
I will try changing the gearbox module myself when it arrives. I just hope the transmission has put itself into Park when I turned it off.

 

Car details? You posted too few!

 

Check the bolts holding the transmission cable on the left side of the transmission. Many posts on this board about them coming loose on any car with a ZF26HP transmission, regardless of the car model. I tighten them at every oil change because they always loosen between changes.