I have an early 07 XK convertible.
Until very recently both Smartkeys worked correctly.
Thinking it was a battery issue, I replaced both smartkey batteries with new Duracell 2032 cells.
These new cells have a best before date of 2030 and have a no load voltage reading of 3.29 volts.
If either smartkey is inside the car, all features work fine but outside they appear dead.
Trying the smartkey while walking around the car, no joy.
BUT if I hold the smartkey within 4 inches above the convertible roof fabric, all features work fine.
It seems to me that the smartkeys are ok but can't find the car through the sheet metal or glass.
I am puzzled by this and would welcome any help.
thanks,
Bob

 

Are you saying the keys won't unlock the car from outside? What are you trying to do with them that isn't happening from outside the car?

 

Had similar symptoms when I first used no name Cr3032s in one of my remotes.

Could these be fake Duracells ?

Maybe worth measuring the voltage with some load on them.

(or the short circuit current with a multimeter set to 400mA; (do NOT try this method on a rechargeable battery)). If zero or near to zero mA you have your answer.

 

The keys will not function from outside the car unless they are held above the top.
They wont lock or unlock the car.
In the past 2 days I have tried Duracell, Energizer, and dollar store CR 2032 cells from reputable local suppliers.
Both Duracell and Energizer have far out best before dates.
It seems that the car is not accepting their signal.
Bob

 

So if both keys display the same, undesired behaviour and you've tried a few different batteries in each to no avail then that probably rules out the keys and the batteries. What happens if you attempt to unlock the car passively, i.e. just walking up to the door and pulling the handle?

 

Do you get the "Smartkey not found" message on your dash? Even if you don't, the prongs may not be making sufficient contact for the battery to deliver full power to the transmitter.

You have an early 2007. Here's the likely cause:https://www.jaguarforums.com/forum/x...t-found-59953/

 

I agree with Stuart on this. My original FOB (now replaced) had a broken ground prong from the last guy that ham-fisted a battery into it. They are not very robust.

 

I double checked the Smartkey prongs.
All are intact.
The rear of the case holds the battery in position when I turn it over.
I do not get a "Smartkey not found" message.
When either smartkey is inside the car or on top of the convertible roof, all functions work perfectly, such as lock, unlock, headlamps, trunk release, etc.
When engine start button is pushed, ignition comes on.
When brake and button are both pushed , engine starts fine.
It seems that the smartkey is sending proper signal but the car is not "hearing" or accepting the signal from outside the car.
Bob

 

I'm really reaching now, but has anything recently changed on or around your smartkey dock? Maybe something stuffed in the console that could dampen the signal from the FOB?

 

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.
5. 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!

Why is your Smartkey transmitting a weak signal? There are 3 possibilities:

1. Weak battery;
2. Poor contact between the battery and the prongs. Just because "they look OK" doesn't mean they're not stretched. Try inserting a piece of aluminum foil under your CR2032 battery to make it a bit thicker. (Most likely)
3. Circuit board going bad. (Least likely)

Stretched prongs is my bet because your Smartkey is almost 15 years old.

 

HA! I was just going to suggest this! I use my temple instead of forehead though.

 

Problem seems now indeed to be rather on the car side.

maybe the RF receiver or its ancillaries?

Here a recent JLR TSB describing a similar issue on I- and E-pace:
https://static.nhtsa.gov/odi/tsbs/20...89732-0001.pdf

 

I just pulled my 09 R Portfolio out of storage today. When I stored it i put a new pack of batteries in the car just in case i went to pick it up and it was dead. I have a 2025 battery in mine and checked my working remote and it has and it also has a 2025 in it. Mine works fine so perhaps one of us has the wrong battery in it. Mine has worked for over 10 years without an issue so it may be you. Given it is a Jag, who knows, but i did not dig out the manual to confirm but again, i have no issues so double check your book. Good luck and please let me know if I am wrong as I am always glad to learn something.

 

CR2032 is the proper Smartkey battery size. CR2025 will work because it's the same voltage and diameter, but it's thinner and might not make good contact with the prongs.

 

Try the battery size 2035 it is the same as the 2032 except it is a little thicker. That could enable better contact with the prongs.

 

It's easier to find hen's teeth or a needle in a haystack than a CR2035. It appears that the CR2035 is no longer being manufactured.
https://www.cheap-batteries.com/coin...ery_chart.htmlWhat to do now?

Plan B - put a small piece of aluminum foil under your CR2032 battery to make it a wee bit thicker so the stretched prongs make better contact. Don't try to bend the prongs down - they're brittle and if you break them you'll need to buy a new Smartkey.

 

Thanks for the info. I have to believe that i replaced mine with what it came with from the factory but after taking a look at my manual this morning, you are correct, a 2032 is required by the manual. Perhaps Jag was out of them and substituted them in a pinch. I will be returning to the 2032 as specified. Thanks for the info, Always nice to learn something on my Jag. After owing several Jags that were total head aches, this 150 has been one of the best cars i have ever owned and i have owned many. After over 10 years of ownership and 50K miles, the only issue has been the parking brake that needed to be recalibrated after changing out the battery so it was really my lack of knowledge that caused the issue. Thanks again for the info, appreciated.

 

You're welcome.

That's what the button at the bottom right corner is for.
"Always nice to learn something ... "

 

I am embarrassed to say this but this morning I tried the smartkey and it worked fine, same for the second smartkey.
Whatever was wrong has cleared itself after 4 days of sitting parked.
I hope the problem does not re appear at a future date.
I have opened the prongs a tiny bit; be careful with this as they are very delicate.
I have since tried the head trick and yes it gives more range.
I would like to find the receiver antenna and check the coaxial cable connection. So far, no luck finding it.
Thanks to all for their thoughtful and helpful comments; what a great group here.
Bob

 

The Keyless Vehicle Module controls the receiver antennas that are located in the door handles and bumper. I believe that the KVM is located behind a panel in the passenger compartment footwell on LHD cars. See the posts by Zulu 10 in this thread from another Jaguar X150 forum. Note that Zulu 10 is in the UK and his car is RHD.
https://www.jaguarforum.com/threads/...-entry.113760/

Also check the Stickies at the top of this Forum to download the Workshop Manual.

Oh, how I miss the simple life of the good old days when cars had dipsticks, drivers weren't distracted by cellphones, cupholders, and infotainment systems. Most importantly, you could fix it yourself since you could see where it broke because cars had no modules!