03 jag x type 3.0 I was driving home and went to back in car. No reverse. I drove in around the block and pulled in garage. Car had been doing fine no issues. Still runs fine but no reverse.

 

I've moved your question from General Tech Help to X-Type forum. This is the place to post technical questions about your model.

Graham

 

I had this issue on my previous X type, presuming your car is an auto. The fix for me was removing the gearbox ecu, opening it up and cleaning the pcb with electrical cleaner.
I believe others have had issues with the J gate causing similar problems.

 

Hey. I'm having the same issue where my 2003 X-Type would not go in reverse. I recently got it from a friend who had it driving fine until he forgot there was a dip in the road and drove through it at normal speeds without slowing down for it. Since then it would not go in reverse. It drives perfect but reverse it won't do. Someone tried flushing the transmission and other troubleshooting but still didn't work.