If you have an early XK it would be a good idea to remove your right side headlight to see if you have the poorly run wire syndrome. A tech posted here that many XK models had this problem. It's a ticking time bomb if you have it and may save your TPMS module from burning out from a grounding. It's easy to fix. Took me 3 hours and I puttered. At least pop out the right headlight and check it. That's 15 minutes. I just went through this. Since I'm a cheap ******* and refuse to let someone throw expensive parts at my car trying to find the problem I dove in head first to understand this system and solve this problem. I hope it helps. If your car started with the right front "tire not monitored" and then after a while it went "tire pressure system fault" this is definitely for you.

"Tire pressure system fault" seems to be a common theme amongst these cars. The "cheap" fixes are a bad tire sensor or a bad antenna. The expensive ones are a bad TPMS module or receiver or the dreaded "bad wire somewhere". You will get a fault message when the system isn't receiving data from more than one TPMS sensor, the module failed or "other system fault".

The TPMS sensors in the tires are designed to last 5-7 years. They contain non-replaceable batteries. It's getting time to replace your early XK sensors.

I would start by taking your car to any large tire store. Most have a box that can "ping" your TPMS tire sensor. This will tell you if it's good or bad. Before you buy new ones drop the tire pressure of all four tires to 15psi with the car OFF. This change in pressure causes the sensors to send a signal of a pressure change. Now without putting your foot on the brake push the start button to wake up the car. Fill all the tires back up to recommended pressure while the car is on. Take a 6 mile drive over 15mph and see if this clears it. If it's still bad you do NOT have to get replacements at the dealer. You DO have to get the ones that fit your rims properly. ALL US cars use a 315mhz system. 433mhz is for other markets. I got mine from Rock Auto. The Jaguar system is "auto detect". If you replace the sensor a 6 or so mile drive will allow the system to learn your new sensors. Problem solved. Go have beer.

OK so you still have a TPMS fault. You've done all that you can eliminate a failed TPMS sensor as your problem. Next "free" thing to do is check your antennas. They are located in the wheel wells under the fender liner. They look like little tennis racquet frames about 5 inches tall. It's easier to remove the tires for this procedure. For the front remove the forward fender liner. The antennas are toward the bumper and look like this:


Unscrew the philips heads. They are plastic. Remove them and pull out the outer ring to remove the antenna. Test with an Ohm meter. As long as you get something (I got 2.8 ohms) they should be good. For diagnostics I swapped my left to right to see if the failure followed it. Now do the same in the back. If you have a bad one or if the failure follows the antenna you have a bad one. They are around $20. Install it, take a 6 or so mile drive and it should reset. Problem solved? Go have a beer!

So you're still having trouble. At this point it's either a bad module, a bad receiver or a bad wire. I have an 07. I read in a post that the wiring for the right front TPMS/Fog light was poorly run. This was my case. I went through all of the above steps before diving in to removing the front bumper. My TPMS sensors were new and checked for function. The failure didn't follow the antenna swap. Removing the bumper is easy. First you remove the forward engine under cover. Remove the front forward fender liners. I peered into the bumper and....AH HA!



Remove the headlights.

Brilliant! NOT.


These are the TPMS antenna/fog light wires!





Well that's not right! Whoever thought that was a good idea...

Before you remove the bumper get a sharpie and trace the offending bracket on the back of the bumper. This will help you re-route the wires once you repair it. Next step remove the bumper. You can get it off yourself but help putting it back on. I laid a blanket on the floor. I removed the harness from the bumper and found this:


Obviously this had worn through and was grounding out. That metal piece is very sharp. Surprised it took that long to cut through. I repaired the wires and re-wrapped them with quality tape. Next I re-routed the wire OVER the metal bracket. I cleaned the back of the bumper with acetone so the new tape would stick well. I STRONGLY recommend "Gorilla" brand duct tape. This stuff should be on the San Andreas fault. I re-routed the wires like so...


I put everything back together and went for a drive. After about 6 miles the fault vanished! Problem solved. Now I think I'll have a beer!

 

Excellent description, great photos - couldn't ask for more! I'm glad you cracked it.

 

Well done! Kudos deserved!

 

Now come on over to MY house and do it all again. I have beer!

 

Add another to the list of gremlins solved by the battery replacement. A month ago a tire pressure warning on the right front tire came on. The car was new to me, a 2010 XK with only 23k miles. The previous owner had multiple cars and drove the XK only occasionally.

I took the car in to the Jag dealer and they diagnosed a possible bad battery in the tire pressure monitor. They also mentioned it might be the tire pressure module. Sure enough, after $350 to do the diagnosis and replace the tire pressure monitor, the tire pressure module fault light came on and stayed on. Took it back to the dealer and they diagnosed a new module for the tire pressure. They wanted $500 to replace it. I said I would think about it.

I found a module online and found a Jag repair shop that would put it in and program it. I had the appointment set up for Tuesday. Today the grayed out climate control on the touch screen happened. I searched and found a thread that said a weak battery can cause all kinds of gremlins, including the grayed out climate controls. I went out and hooked up a charger and the battery was sucking all it could get from it. The volts were 12.6 with the engine off. But it was pulling like crazy from the charger.

I decided to put a new battery in. Replaced it tonight and set it all up according to instructions on this thread (thanks everyone). While driving around the tire pressure system fault turned to the clock. It did not come back.

Crossing my fingers, but I think it was a low main battery issue all along.

 

Sorry, mixing threads. The battery replacement information was on another thread.

 

Flyc2c excellent post. Makes me want to have a beer.

 

I really hoped this was MY problem, but alas I checked it out and the wire was well above the support and not in any distress.
Oh well.

 

First post here...have the same issue with my 08 XK, after front bumper removal due to fender bender(happened first day I got the car!). TPS fault, and also no fog lights. I will pull down the bumper and headlamp and check for cut wires and update. Great post, Thanks!