I need some help. Let me start from the beginning. My son, 21years old is driving this car normally. The smart key fob lost its programming and did not work. he could not lock the car unless he used the metal key.
The car started from the key slot under the dash. He took the car to the jaguar place, they told him it would probably be more than $800.00 because the had to trouble shoot and replace a component. I started thinking what could have gone bad. After reading all posts and threads and watched YouTube videos I came up with 2 possible problems. #1. The central locking radio receiver. Located under the head liner in the back ceiling.. #2. The keyless vehicle module. Since the car starts from the slot I did not think it would be the CJB (central junction box ) programming. Out of the 2 possibilities I ordered a used (keyless vehicle module) from Ebay. $75.00. I only had regular obdII scanners so I ordered OBDSTAR Model X-100 & cables for eeprom. $230.00 This is so I could try to reprogram the key fobs after changing the keyless vehicle module. I changed the module and started programming the smart keys. (It was semi success full.) after programming the keys can turn on the light, unlock the car ,lock the car & open the trunk. So far so good. I still have to put in the key in the slot to start the car and now I can lock the car with the smart key. However I can not start the car with just having the key fob inside the car. Since I could program the keys I think the central locking receiver is good. I need help from someone whom is more educated on this overengineered system than me.
Please do ask me to check batteries in key fob or main battery. I do not have any trouble codes when scanning. Maybe sticky can guide me to the right person? Car is Jaguar XF 2011 x250. I believe the model was between 2009 to 2013.
I have been thinking of trying to update the car with the latest software but not sure how to do it.
Thanks for any advise.

 

Sorry to disappoint you, but one of the very first steps in any electrical diagnosis is confirming available system voltage.

Using a voltmeter across the battery terminals, with the ignition in the OFF position for a minimum of thirty minutes, what is the voltage indicated on the voltmeter?

 

NBCAT, thank you for trying to help me. The car is on a trickle charger and the light is green, fully charged.
I was thinking since I bought a used KVM from ebay it could be something wrong with it. Just need to have a confirmation that the KVM takes care of the starting procedure when you have the key in the car. if so, I might buy a brand new KVM.
Thanks

 

This is an update of my key fob not working inside the car.
I took the car to the dealer because the only thing left was to reprogram the cjb ( central junction box ). I was right it had lost the programming. They programmed the CJB and it took care of the Passive starting mode. That was what they called it.
If the programming was not lost it would have worked by reprogram the key fob with the X100 Pro ODBII. they only charged me $205.00 . I guess it was for 1 hour.
Hope this will help some one in the future that has the same problem.

 

don't disconnect the battery or ever let it die

 

A battery only last between 3 to 5 years. no other choice.