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Key fob issue

Stefi 888
Posts: 27
Joined: Sun Jan 14, 2018 8:29 pm

Key fob issue

Postby Stefi 888 » Sat Mar 03, 2018 10:47 pm

Hello, i have recently received a pair of IR Fob/receiver and was warned that it does not work, however, having fitted the receiver to the car and put new batteries in the fob, by God the Jag locked, i was so happy, but i soon understood what the man meant by not working, im having problems with the fob, as it does not seem to want to work all the time, i think there is something wrong with the contacts and it only work when the battery contacts are touching the batteries in a certain way, as soon as you move it slightly, it does not work, has anyone had this problem? i have tried using contact spray and scraping the contact plates a bit but no change at all, i don't want to try to pry the fob open as i am notoriously clumsy and am afraid of breaking it and loosing the signal forever, so does anyone know the remedy? alternatively does anyone know a way i could record the signal and possibly program my phone or a universal remote to unlock my car, or at least keep the signal so i would not loose it if i pried the fob open and possibly messed something up?

thanks in advance!

Snr Member
Posts: 416
Joined: Sun Apr 19, 2015 10:36 pm
Location: In a garage

Re: Key fob issue

Postby SovverBovver » Sat Mar 03, 2018 11:24 pm

I heard these fobs can develop problems with the contacts in the button. It might work better when the button is pressed and wiggled slightly.
1992 Jaguar Sovereign

Posts: 1431
Joined: Tue Jun 29, 2010 4:20 pm

Re: Key fob issue

Postby M-e-l-l-o-w » Tue Mar 06, 2018 1:43 pm

The fault could be faulty switch contacts or perhaps more probably a broken solder joint in the remote fob.
As these can easily get dropped they can suffer with breakages inside.
Your options are:
Get another identical key fob and program it to your car.
Take the one you have apart and fix it!
As you state that taking it apart is beyond your skills then the only option is a replacement remote.

Could you also please add your car details to your group signature so we all know what version of the XJ40 you have as this makes a big difference when sorting out faults.

2004 (Facelift 05-MY) 4.2 Jaguar S-Type R in Black.

Morocco Red / Magnolia 4.0 Sovereign Auto Vin.708xxx.Insurance write off on Friday 13th March 2015.

Posts: 1195
Joined: Tue Oct 16, 2012 6:50 am
Location: Vancouver Island

Re: Key fob issue

Postby abercanadian » Tue Mar 06, 2018 6:01 pm

I suppose I have a later fob because there are 2 screws that hold the halves together ..In my case the remote failed because the button hinge snapped making the button stay in the presssed position with no "springback".

I repaired the hinge several times with Krazy glue, each repair lasting maybe a few months. Eventually though, the hinge was so messed up that the glue wouldn't work any longer. Desperate to find a solution, I determined that I had to figure out a way to stop the button arm moving from side to side and place something under the arm to allow the button to "spring" back up.

What I came up with has worked without a problem and still works to this day. I cut away the hinge support with a sharp blade then put a blob of hot glue in its place and under the end of the arm. While the glue was still hot I reassembled the remote to allow the button to align itself with the aperture in the upper part of the case.

When the glue had cooled down, I checked the mechanism and it worked properly. The hot glue, (which is quite "rubbery") had just the right amount of "spring" to compress and allow the button to move down and back up. This repair should last forever as there is really nothing mechanical involved in the button operation any longer.

Hopefully this will help someone else with a faulty (late) remote control.


94 XJ40 VDP vin 701729
Oyster Metallic/Doeskin on Aero Alloys
230,000 Kilometers 143,000 Miles
Daily Driver

94 XJ40 SOVEREIGN vin 703632
Diamond Blue Metallic/Barley
111,000 Kilometers/69,000 Miles
Parts Car

Stefi 888
Posts: 27
Joined: Sun Jan 14, 2018 8:29 pm

Re: Key fob issue

Postby Stefi 888 » Fri Sep 14, 2018 12:44 am

Just to post a reply, i have finally fixed the issue, for some reason there is room for three button cell 3v batteries however, the fob needs only two and it gets too much voltage when three are present so i put two batteries and a piece of tin foil in between and works like a charm! :D