Hello all. Hoping for a bit of guidance. Owner of a 2008 XKR. Last week my key fob died. Car had been giving me the error message that the fob battery was low, even though I had changed it only a couple weeks earlier. Took it to local dealer who told me I need to replace auxiliary junction box and order two new key fobs for the car. They also told me that Jaguar no longer supplies the auxiliary junction box so good luck.

Two questions: first, is it possible to diagnose whether I need a junction box or whether trying to buy/program a new key fob would work (I've read the forums on how to make that work) without having to buy and install both? Second, if I need to replace the junction box, does anyone know where I can find one? The internet has been little help on that.

Thanks in advance for any assistance.

Matt

 

I would try doubling up the battery to make sure the contacts in the fob haven't loosen up over time.

 

Do you get a message on the panel: "smart key not found"? Do you have a spare key? Tried putting fob in center console slot? Try tweaking battery contacts in the fob, as in previous message. Methinks the dealer is too keen to sell you a "fix"...

 

Thank you for the replies. I suppose I should have added those details--apologies. I have the message "smart key not found" when I try to start without the fob in the receptacle in the center console. The car will start with the fob in the receptacle in the console so I can drive it. I do not have a second key. When I bought the car it only came with one and I failed to ask about the second. I fiddled with the contacts in the fob to make sure they contacted the battery, but it's difficult to tell if they stay where I put them when I re-assemble the fob case. I also detached the battery leads and completed a hard reset for the car.

I have not tried doubling the battery. Is that literally adding a second fob battery over top of the first in the fob?

And I concur about the dealer and the fix--I have steered clear of this dealer as much as possible because they haven't always been terribly eager to help. They are closest to me though so I figured the risk was worth it. Egg on my face--again.

 

DO NOT TRY TO ADD A SECOND CR2032 BATTERY! It won't fit, and if you break a prong you're screwed! You will have to buy another Smartkey and have it programmed to the car.

If you suspect that the CR2032 battery is not making good contact, take a small piece of aluminum foil and make a tiny shim to place under the battery. Make sure to not bend the prongs because they can easily break.

Are you certain that your "new" CR2032 battery is fully charged? Do you have a coin battery tester? If you bought it on the internet for cheap, it may be old stock and discharged. Is there an expiration date on the package? Even if it's it a name brand, it could be a cheap Asian clone. Buy your battery from a Big Box store where you can check the expiration date and be confident that it'll work.

Good luck!

 

+1

As it is communicating with the vehicle (or it wouldn't start), the issue is likely to be sub standard CR2032 battery or smartkey contacts.

Graham

 

You will find that If the battery is placed in the slot, that the FOB should be recognized even with a depleted battery. (Its called RFID).
If placed in the slot and not recognized, there is an issue. If both fobs don't work, the issue is probably not with the fob but...

Codes would help!

 

Since you say it works fine with the fob docked, then it's likely the fob battery or contacts as others of already suggested. Also, wouldn't be a bad idea to get another fob. You'll need your current one handy when programing the new one so it's not "orphaned" or un-paired to the the car. A main dealer or specialist with SDD can do this for you or you may find a key service with the tool to do this as well.

 

Code was U3000-49. Battery was big box store and major brand name purchased in person, but I am more than happy to try another battery or pack of batteries. Car is getting brakes and back end done so when I get her back tonight I will try the aluminum foil with the fob connectors.

Huge thanks for the replies so far. Love driving this car so I need her at her best.

 

Are you sure about that code?





Taken from the DTC decodes in the Workshop Manual.

Graham

 

Matt:
I also own a 2008 XKR, and for the first six months, I was changing fob batteries every 6 weeks. It wasn't until I learned how to correctly re-assemble the fob that I stopped replacing the batteries. I did order new fobs as the older ones were showing wear and I transferred over the internals but my assembly was not correct; it seemed like I had to make extra effort to get the button to click internally, and that's what I fixed. OF i remember correctly I was able to assemble half of the fob without adding the top and I could feel the proper "solid" clicking response. I haven't changed batteries for 18 months! Moral of the story: Operator Error!
Rick

 

Ha. I am sure that that's the code written on my dealer paperwork. Seems that that code is for my adaptive headlights....

I just got my car back last night after getting the brakes and rear end done. I tried the aluminum foil for the battery contact and no joy. I will order a fob or two and see if my specialist dealer can reprogram. Thanks all for the help on this.