to make a very long story short my wife's X-Type had been periodically stalling or stuttering at low speeds. Finally the tensioner for the water pump belt gave out . After some research I decided to replace the water pump, the tensioner and the starter which was also giving signs of going out. In the process I did a thorough cleaning of the throttle body as recommended in other threads related to stuttering. So the car starts fine feels fine for the first test drive which was short. Then next morning car stalls after half a mile and transmission fault message goes on as well as a check engine light. I'm getting the codes listed in the subject line and completely baffled. I would appreciate anyone's input on this

 

P1796 = CAN Controller Circuit (Bus off). Can't help with that, but the P1000 is just telling you that it is going through a readiness test checking all the systems codes.

 

In reading the work you performed I would think you need to go back over the steps and check the connectors around the throttle body. Especially the 2 wire connector below the throttle body. I think a connector is not properly seated or could have a broken wire.
Reexamine the steps of your work and recheck each connector. I am assuming you removed the throttle body for cleaning. If you didn't then remove and clean the plugs for each connector on the throttle body and do a hard reset. Check and clear the codes before starting the engine.
Let me know how you progress. The P1000 is normal as stated by higeorge it will turn into P1100 when all checks are completed and satisfactory.

 

Typo. P1111 not P1100