Hi all,

I’m a new member to this forum but have been a frequent visitor in the past to research questions about vehicles I’ve owned. I have a question which I haven’t been able to find anything on.

My keyless entry works fine if I’m very close to the car but I have to be really close to the doors and it won’t work at all for the trunk / boot.

Also, if using the buttons, I have to be very close to the car (within a couple of metres) and doesn’t really work from behind the vehicle.

The start button works fine. Don’t think it can be a fuse as keyless entry or buttons wouldn’t work at all if it was. Has anybody come across this before? It’s a new battery in the key. I’m

 

Should have said, it’s an 08 model XK

 

it may be a new battery. Is it a quality battery that has not gone past the expiry period?
Also, the receiver in the boot lid has been known to either come loose or perhaps its fine, but the button has worn??
Another common issue is that the contacts in the fob are not firmly planted against the battery.

To aid many of us it would be helpful if you put your car model and year into your signature. You will find the link by selecting the user icon in the top RH corner.
Cheers.
And congrats on your first second post. It seems we cross posted.

 

Signature updated, cheers

 

The battery was an Energiser and fairly recent purchase so should be okay. The FOB is in pretty good condition and isn't showing a lot of wear (the car has done on 47k kilometres). I was wondering if maybe the car battery needed replacing - I have noticed with previous vehicles (Jaguars) that once the car battery starts getting a bit old the electrics can start to play up.

 

Any idea where the receiver is, how I access it?

 

I noted that you're in New Zealand. Your problem appears to be a weak signal from your Smartkey transmitter. Just because it has a new battery doesn't mean that the battery is strong, especially if you bought it on the internet for a low price. You can test it with a voltmeter. I'd buy a new brand-name CR2032 battery locally so you can check the date code to make sure that it's fresh.

You should have two Smartkeys. Does the second key work any better? If so, swap the batteries and see what happens.

It's possible that the CR2032 battery is not making good contact. The prongs that secure the battery inside the fob often stretch with age and repeated battery replacement. If that happens to your fob, don't try bending the prongs because if they snap off your fob is toast and you'll have to replace it. To maintain a good connection, use a small piece of aluminum foil to make a thin wedge to place under the battery so it fits snugly under the stretched prongs. Note that the slightly thicker CR2035 is no longer available.

Read this thread:
https://www.jaguarforums.com/forum/x...oncern-247003/

Good luck!

 

Thanks Stuart - will give it a try

 

The battery was bought at a local store and is an Energiser battery so a respected and reliable brand. Only have the one FOB unfortunately (do have a spare one from an XF but they can't be reprogrammed apparently). I tried the foil under the battery and don't think it made much difference - hard to tell but I still have to be in very close proximity for anything to work. I'm wondering if the receiver end is the problem with low battery. I might pull it apart and have a look at how old the car battery is. I just know that changing the battery resolved a number of electrical gremlins in both my XF's.

 

Welcome from fellow XK owner in Bay Of Plenty. I have been on the forum for a couple of years and it has proved to be invalable.

 

From the manual:GENERAL INFORMATION ON RADIO

FREQUENCIES

Note: The radio frequency used by your Jaguar Smart Key may be used by other devices. For example: amateur radios, medical equipment, wireless headphones, or other remote control devices. This may cause the frequency to be jammed, and prevent your Jaguar Smart Key from operating correctly.

Environmental conditions can affect the operation of your Jaguar Smart Key and the operating range may vary considerably depending on the vehicle's location.

Test the battery with a multimeter though if the signal is low, you will get a code thrown.

Also, you should be with one meter of the car for the remote FOB to receive a signal from the Low Frequency antenna and then transmit via RF frequency back. There are 6 low frequency antennas in the system. You have two in the back - One at the battery brake and one behind the rear bumper cover. They may be causing your boot issue. They both look like this:

 

thanks Sean, I’ll check the battery with a multi meter and see what I get. The environmental stuff shouldn’t be an issue, this is the 4th Jaguar I’ve had and never experienced an issue before so it’s either going to be the battery or the receiver I guess

 

If your car is a Japanese import I suspect you are experiencing the low power output from the fobs for that market. They are unique to the Japan and both my '10 and '07 XKRs had the same issue so I suspect it is normal.

I have to stand in a very specific place and almost 'hump' the rear bumper to get the boot open using the tailgate switch and can't unlock the doors from much more than 10 or 20 feet away.

 

Just out of curiosity, try this.
1. From outside the car, use your Smartkey to lock and unlock the car.
2. Move 6 inches away from the car and repeat Step 1.
3. Repeat Step 2 until the car no longer responds to your Smartkey. Mark that spot - it's the Initial Maximum Range.
4. While standing on The Spot, face your car and hold your Smartkey to your forehead (stop laughing, I'm serious!) and push the buttons to lock and unlock your car.

Did that work? If so, then you just proved that the weak signal transmitted by your Smartkey got stronger when you held it against your head!

 

haha, I’ve actually tried that before and it worked!

 

yeah I managed to get the key to work yesterday by holding it against the boot and then opening. The car is a Japanese import so if what you say is correct, I might just have to live with it.

 

Well Stuart, you’ll be pleased to know it worked stood a few metres in front of the car, held the key to my head and pushed the boot release button and ….. low and behold, we hear a click and see the lights flash. Go figure huh.

 

but is your brain supposed to glow green??

 

I hope it works with beer



Seriously though Stuart. Thank you for posting this.

 

With the fob in my right pocket, I find standing close and just to the left of the number plate works best for me.