Background: About a month ago the wife and I took our XJR (2000) away into the country for a getaway. We were about to leave the BnB on the next morning, but the remote would not open the car..... I called the roadside service company that I subscribe to, and a man in a van attended. He pulled the remote apart (as I had already done), but didn't have the right size replacement battery on board. After some haggling he gave me a lift to the closest big box store, and I purchased 2 new CR2032 batteries (1 spare). Arriving back at the car and fitting the new battery did not bring the car to life. So he jemmied the door (I had to look away) and unlocked the car, at which point I hurriedly put the key into the ignition to shut off the alarm.Anyway, we continued on our way and didn't lock the car at any other stops on the day.

When I got home, I pulled the remote, and the inoperable spare that I had, fully apart, including removing the rubber around the circuit board. Both remotes were filthy on the button side, so I carefully cleaned all surfaces with contact cleaner and cotton buds, and re-assembled them completely. AND BOTH WORKED PERFECTLY!

After using the car that day, I put her away again and life happened for a few weeks. Then, just the other day, I decided to take the XJR out for a run with me to golf. And at the course, of course, the remote didn't work again (neither did the back up, which I had taken with me out of a sense of safety...), and so she was left unlocked again. I got her home and put her under her covers in the garage, with the remotes still not working.

So - the question is - which on car module does the remote work with? Where is it on the car, and is there a known problem like this?

All help is/will be greatly appreciated.

Lyndon
SW Sydney, Australia.

 

Oh - and between the weekend away event and the next use (to golf) the battery had died completely - not a skerick of voltage when the mechanic tested it. So a full battery replacement (hence - hard reset) has occurred, and not fixed the problem.

And - I just went out to the car, minutes ago, and both remotes now work! Sheesh!

Lyndon

 

It's called a security lock module and it sits under the fuse-box in the back of the boot, hence easy to access - I mean the fusebox. I think you need to unscrew the fusebox to get to the module. The following video drags on a bit, but if you watch briefly from time 4:20, you'll see, where the module is located and that your issue might be corrosion on the module's PCB. Your problem could also be cold welds (i.e. soldering contacts, which have "hair"-sized cracks), only visible, if you check very precisely. Re-soldering them would solve the issue, if that is the problem - I always heat up the soldering iron first and then disconnect it from the power-supply before soldering, to avoid damage to the PCB due to sparks from the grid.

 

CR2032 is wrong battery. It measures correctly but voltage is wrong. There should be two CR2016 batteries. 2016 is 50% thinner than 2032 but same voltage. So as correct is 2x2016 in series(top of each other) voltage is 6V instead of 3V. Remote works with the 3V but it is very weak and how close car reads it varies a lot.

 

Lyndon, what does your remote look like? Is it the Flip key? The Flip Key uses 1 x 3V 2032.

 

Peter

Thanks for that link. I have watched it and now know where to find the module.....

Going to see if I'm game enough to pull out the fuse box for an inspection, or tell my mechanic to have a look. I wonder if there are any complications from replacing the module with a 2nd hand unit?

Vauxi

You are correct, the car's manual does say 2 x CR2016 batteries. So I immediately shot off to the local shops and bought 4 new ones.... And after making the change, NEITHER remote worked..... . So, I put the CR2032's back in , and the main remote worked, but not the spare.... Also, the wife was astounded that someone from Finland was assisting me way down here! Cheers!

Peter

The remote is:



Yesterday we used the car to go to my parents retirement village for an outdoor picnic for my mother's 86th birthday. I wasn't game to lock the car, so just left it unlocked within view. Driving the old girl is such a joy!

Now to decide what to do next....

Lyndon

 

OK, I can't tell you about the batteries in that remote of your - I have only flip keys now.
I did once have this remote, which you have - one of those remotes came with my XJ8 1998 - buy I can't remember which batteries it used - I sold it meanwhile - and the troubling thing about that one is that you cannot buy more of those. I like to have 4 keys for each of my cars.
Plus, I like the flip keys much better.

Thus I did something "daring" back then and it panned out:
Even though that one remote worked and my module worked I did research and come to the correct conclusion:
Newer versions of the XJ8 (I think after 2002) have a different version of the security module installed. I got myself a second hand module - I think from a 2002 XJ8 from the UK and swapped it for mine. And then I successfully programmed the transponder and remotes of 4 flip-keys for that XJ8. I had to file a bit of plastic off the housing of the flip keys, as the XJ8 uses 8-cut tibbe keys, while the OE blank blades of the flip keys are just for 6-cut tibbe key blades (I used normal 8-cut blades with a plastic grip, removed that grip and it fitted the system used in the flip keys).

 

There is something clearly wrong with youre fob's. Those contact pads at the top of the fob can be slightly bent away so that battery does not make a contact anymore. Bent them slightly to the battery direction and try with correct batteries again. When the fob doesn't work, is it that any of the buttons does not work ? It seems that Finns are everywhere.