I washed the car and drove it for a mile or so, turned off the car and when I got back in and started it up I see the ABS light, it goes off and on intermittently. Stays on after start up and drive but will not come on the next time your drive it. Took off the tires and noticed the car is due for brakes shortly. At the same time I am now getting the P1000 code. I clear the code but it comes back. It's also intermittent. WTH? There doesn't seem to be a definitive answer for this code when I did a search. I'll do the brakes first and for the code maybe I'll take it to the dealer if I must.
I don't think the two are related, just seems odd.

 

Did you power wash the car under the wheel arches and in behind the wheel hubs?
Possibly you might have driven some moisture into one or more of the wheel sensor connectors if you were unlucky enough to get a sufficient direct hit.

The P1000 has anything to do with it.
This link might help explain the code origin.
Jaguar X Type OBD ENGINE MANAGEMENT CODES P1000

 

Every OBD clear causes P1000 - look up what it means for a Jaguar or use Search.

 

I would bet the car needs a tune up, original plugs on 110,000 mile car. (Engine light)
The ABS light is still on, brakes look good, 75% pad left. Pulled out sensors, cleaned and dry no problems. Maybe a bad ABS sensor?