Hi all,
I thought I’d introduce myself after browsing this site for such a long time. I bought my first Jag 8 years ago, a 1999 Daimler V8 LWB in somewhat nice condition. I used it as my daily for about a year, during which the car developed a few issues that were no longer economical to fix. It also had the nasty habit of shutting down the engine on the highway when the cruise control switched off.
After that, I drove a 2.0 X400 X-Type, which to be honest was a great little car. Nimble, quite speedy, and I feel also good looking. It felt more sturdy than the X308.
But; after a few years I started thinking about owning a X308 again. The impracticality be damned, it is just a so much more beautiful car than the X400… I bought a really nice looking low mileage Westminster Blue 4.0 SWB Sovereign, which I’ve been driving ever since. I love it, for all its quirks. hopefully this one is going to stay with me for a very long time.
I wanted to share a technical issue (and solution) to a problem with the Sovereign which somehow took all of my Google-fu to solve. I hope that sharing it here will increase the chances of other people finding it. Probably there are plenty manuals online describing the issue, but more is always better, right? Maybe it is a very rare problem, maybe not. Who knows?
The problem was that my remote keyfob was behaving erratically when locking the car. it started missing maybe 2 out of 10 attempts to lock the car. The car just wouldn’t respond to the lock button. If the car did respond, it would then lock and unlock just fine until after a while it wouldn’t anymore. The amount of errors kept increasing over time, until more than half the time it woulnd’t respond.
I tried other fobs, reprogramming, new batteries, checking the connections to the security module in the trunk, but nothing helped. the garage advised me to order a new fob, which I’m glad I didn’t get. During one final afternoons googling I found a forum mentioning the same problem in a Ford. I cannot remember the source unfortunately. And it contained the solution! Spoiler: There was nothing wrong with the electrics of the car, and all my keyfobs were fine.
There is a microswitch in the ignition lock, activated by moving the small metal lid covering the barrel, that tells the car there is a key in the ignition. This stops the car from listening to the keyfob, so you will not accidentally lock the car and set the alarm when driving. this mechanism had acquired some dirt over the years and sometimes it wouldn’t close the lid upon removing out the key. This caused the car to think there was still a key in the lock, and thus ignore the keyfob. From the cars perspective everything was working fine, and there were no errors. A bit of paper and a drop of WD40 and the mechanism has been working ever since.
Anyway, long story. hope this will help someone 
thanks for reading,
Paul