Hi all X-351 fans, I'd appreciate your help on a problem with my 2011 XJ L.

Two fobs were delivered with the car and worked flawlessly for years. Both have fresh batteries. Here's the problem now:

-Key fob #1 transmits on 315 MHz as verified by a spectrum analyzer but appears to have unpaired itself from the car, or its programming is corrupted/missing, because the car no longer responds.
-Key fob #2 will only intermittently transmits and, when it does, the car responds as it should.

I have a used clam shell fob coming that will need programming. What are the best (and least-cost) solutions to program the replacement fob and to get fob #2 to "re-pair" to the car?

Thank you!!

 

With fob #2, have you removed the board to check it is not just dirty contacts?
I know you fitted fresh batteries, but have you checked they are actually still good? I've given up buying the batteries online now as they always seem to be discharged, or only last a few months. My local dealer charges £2 each to supply them and they have always been good.

Fortunately on a 2011 you can program new keys to the RFA/KVM at will, unlike the 2016+ cars that use write-once coding.
Unfortunately, if you lack access to the required diagnostics software then the best bet is to find a good JLR independent or auto key specialist who does and pay for an hour of their time.
You will need all the keys you want to program to be present, so you might as well try and repair fob #1 at the same time.

 

Hi @xdave and thank you for your thoughtful response. Unfortunately, FOB #2 is just highly intermittent at transmitting. I've cleaned the PCB with TechSpray (great pro PCB cleaner, IMO) then examined it under a 10x binocular microscope for any damage (none found). I also confirmed that the 3V from the battery are making across the vias in the PCB and onward to the chips. Alas.

I purchased a new key and will likely have to take it to my friendly JLR dealer but I might try using the SDD-130 programmer....time will tell.

Again, thanks for considering my problem,

Robert

 

Robert,

Try replacing your CR2032 battery with a thicker CR2035.

Changing the battery can stretch the prongs that secure the battery, thereby causing intermittent contact with the battery.

Dimensionally, the CR2035 is almost identical to the CR2032; the only difference is that the CR2035 is 3.5mm thick - 0.3mm thicker than the CR2032. They're both 20mm in diameter. That additional thickness can compensate for the stretched prongs, without preventing the fob case to be properly closed.

It's worth a try. Just make sure to buy it locally from a chain big box or drug store, so you can check the date code for freshness and know it's a genuine name brand and not a cheap Chinese knock-off.

Stuart