Hi guys,
This could be a long story so get a brew going first. I'll wait for you.
OK now?
It all starts when both of my alarm fobs decided to only work the doors and alarm if they were right up to the door handles. This in itself is very strange because I have heard tell that the sensor for the alarm fob on a Jaguar XJ6 (X300) is at top centre of the rear window. That's what I heard, anyway.
So I went to eBay and bought a card of 12 Panasonic CR2016 for £3.00. I changed the batteries in both fobs and they seemed to work only a little better but the point to remember is that they DID work.
Keep that fact bubbling away at the back of your mind.
Within 4 weeks, the fobs both died on me. No big deal because I could still use the keys to lock/unlock the doors and set the alarm. But then, in a sort of, "I'll try anything" mood, I decided that re-programming the key fobs wouldn't do any harm. So I did.
I replaced the batteries again and re-programmed both of the fobs. It's fairly easy to do if you follow these steps. It's easier if you separate the alarm fob from the ignition key .......

1 ... Open driver's door and boot lid. Turn ignition on until warning lights appear.
2 ... Open centre arm rest and press the Valet rocker switch 5 times.
3 ... You will hear a chirrrp noise which means that the system has gone into "Learning" mode.
4 ... Press the "LOCK" button (the larger of the two) on your alarm fob. The system will give you another chirrrp to confirm that it has received the signal. If you do not hear a single chirrrp but you get 2 chirrrps after 15 seconds, it means it's failed to receive the signal and you need to start over.
5 ... If you get the chirrrp to say that the signal HAS been received you can programme another fob by rocking the valet switch once. Do this within 10 seconds or so. If you delay, the system will think you have finished and exit Learning mode. The system will chirrrp twice to confirm. Press the big button on the second alarm fob.
6 ... When you have finished programming all of your alarm fobs, wait 15 seconds for 2 beeps.

So that's what I did with my alarm fobs and they worked as alarm fobs should. They lock/unlock the doors and set/unset the alarm from 20 paces behind the car (maybe more, a wall stopped me from going further back) They also work from my armchair through 2 brick walls.
At this point, and having been told of alarm fob batteries lasting 2 years or more, I experimented. I put the old, dead (??) batteries back in and re-programmed the fobs again. Now THESE batteries do everything you would expect alarm fob batteries to do and from the same distances as new batteries.
OK, remember that fact that you are keeping at the back of your brain from earlier? Bring it back to the front.
It seems that re-programming the alarm fobs made them work as they should BUT they were already programmed for my particular car, otherwise they would not have worked at all. If removing the batteries for 5 minutes or so meant that the fobs need re-programming, how come the fobs locked/unlocked the doors and set/unset the alarm BEFORE being re-programmed, albeit from a lot shorter distance?

My head hurts now. What the smeg is going on? .

 

Hi 5tevie, must confess I've read your message several times and I still don't fully grasp it but that's probably more a criticism of me than you!
Firstly, why, when putting batteries back in, did you re-programme? Only after 2 minutes without batteries (or a bit more) should that be necessary. Just swap them.
Finally, I'd be very cautious about buying batteries off eBay. Are they genuine? Why did you need 12 anyway? Far better I would have thought, to buy 2 locally from a trusted outlet which you can be more certain stocks genuine items. As you say, they should last a couple of years so by my calculation you bought enough for the next 12 years!

 

Hi biffta,
Simple answer first. I bought 12 from eBay because the seller had glowing feedback for thousands of sales relating to all kinds of batteries including the exact same batteries that I needed. I also got them because a friend of mine also has a Jag so the original idea was that I could give some of them to him. Lastly, I bought 12 Panasonic batteries with a use by date of 2020 for £3.00 inclusive of postage. To buy 12 x CR2016 batteries in a local shop would have cost me £6 (£1 for 2)

As to why I re-programmed the fobs after putting the new batteries in, it was just a case of trying all I could think of to get the alarm fob working as it should re the range. I had folk telling me that thei fob works at 30 yards and through walls but mine still only worked at very close range. My mind just said to try all I know which was basically to re-programme the alarm fob.

The other bit may be explained by saying that when I first decided to change the batteries, I took the old batteries out and then had to hunt around for the new ones where 'er indoors had stored them so it was probably more like 20 minutes before the new ones were in place.

 

Here is some info for North America but most of it will be relevant.

Look at the fault diagnosis TSB.

bob gauff

 

Just for information, on the X300 removing the batteries from the remote fobs will not cause reprogramming to be necessary. They can get out of sync, but unlocking the car with a key, and pressing the remote lock button up to three times will re-sync them.

Cheers,

 

Hi there xjrguy .... Could you please explain what you mean by "They can get out of sync, but unlocking the car with a key, and pressing the remote lock button up to three times will re-sync them."
I have only owned a Jag for a couple of months and I have not come across the expression "Out of sync" before.
Cheers,
Steve

 

Steve,

I have to run right now, but I'm sure one of the bulletins Bob posted for you explains it. Check them out.

Cheers,