I shoulda just checked the TPC receiver in the overhead! It plainly shows 315Mhz on the device. I ordered some Jaguar ones from Ebay today. We'll see what happens once I get them installed. Will probably be a couple of weeks but will let you all know the outcome.

 

If that's true his 2015 should be fitted with a 433Mhz receiver & wheel sensors.

True, that is the best reference - even better than what a dealership should have been able to tell you, because it's not likely but very remotely possible that a previous owner may have replaced the original receiver with a replacement of the other frequency; again not at all likely, but if rothwell is correct it would suggest your 2015 was built with a 433Mhz.
Not that that matters because you visually confirmed what yours actually has.
That said, I hope the genuine sensors you bought on Ebay are new, healthy an in fact genuine.
The sensors that were in our X351 when we bought it were the right (315Mhz) frequency and they were healthy as far as the batteries & operation, they just weren't the right ones for the X351.
The ones I replaced them with were preprogrammed and required nothing to be done once installed, these:
More Information for VDO / CONTINENTAL SE52029
Since getting these installed our TPMS has been working as designed.

 

Thanks for the info JagMark! I'm an optimist and expect the sensors I ordered to work since they are jaguar brand, in the package and confirmed they fit my car. If after they are replaced, I may try replacing the receiver or control module to end the dash warnings!

 

We hope it takes care of it too, just have heard too many stories (and have experienced a couple over the decades) of bait & switch on Ebay although the large majority of sellers are trustworthy.
Keep in mind that it may take a few miles of driving at reasonable speed for the system to identify & interface the new sensors after they're installed, so it's not going to change from the warning immediately.

 

I want to thank everyone that contributed some ideas to the TPS problem of my 2015 XJL. Turns out it was not the TPS sensors in the tires or the modules that they connect to. It was an intermediate connector which had been compromised and was corroded. C11 is the connector which connects the front TPS receiver antennas to the front interface/ engine fuse box. It appears the connector was not fully seated and water had been seeping into it for some period of time. Once the contacts were scrubbed, sanded, scrapped clean, and sprayed with some contact cleaner and Deoxit, the warning has not appeared after a few days of driving! Not sure if there is a way to view any information relative to the state of the tire pressure in the instrument cluster but at least I don't have that same warning on the dash whenever I start the car.

I wanted to trace the antennas to where they connected to a termination location. Looking at the electrical diagram, I found the front antennas connected to the "Junction box-central" through the C11 connector. (This connector also joins the front parking assist sensors; the left one was not working on my car as well.) The connector is supposed to be affixed to the back of the front bumper but it was not; just hanging free in the cavity behind the bumper in the wheel arch. At some point,( before I owned this car), someone was fooling around under there and did not secure the connector into place and did not fully seat the connector. Water must have been seeping into there for a number of years I'd guess.
This kind of poor servicing is just not acceptable to me. Always make a quality repair and bring the car back to original condition if at all possible. This would have never happened if someone had merely seated the connector and secured it as manufactured. OK, off the soapbox. Good night!
Diagram attached under the photo.