Central locking weirdness - explanation?

[HPsauce]

I've noticed a few times in recent days that my remote doesn't work to unlock the car or open the boot. After a short while and a few prods it usually starts working and is then fine.

Today, same thing, so I thought - maybe batteries needed, though I think it's not that long since I changed them. Old ones were still over 3V but I installed a new pair of CR1620s anyway. Still not working.

Tried the spare key, not used in ages, worked fine.

Unlocked the car with the bad remote using the drivers door lock, fine, then started the car.
After which the remote was working again.

I really haven't a clue what's going on, is it somehow getting "out of sync"? Is someone trying to remotely unlock my car assuming it has keyless entry/start? I'll see what VCDS says, if anything.

Any thoughts anyone?

[HPsauce]

Originally Posted by HPsauce

I'll see what VCDS says, if anything.

Well VCDS said "00955 - Key 1 09-00 - Adaptation Limit Surpassed"
I have no idea how or why, or what the limit actually is. The key just sits unused in a small cup, I don't carry it in my pocket where it could be triggered, except when I take the car out.
Unlocking the car with the physical key and starting it seems to have reset things - is that normal?

[Mrfaz]

Hi hp I've had the same thing show on vcds and have actually ended up locking my self out twice as the rod that connects the barrel pooped out and I popped it back in. Today it decided to pop and had to get the aa to get me in. I have 2 keys but only one fob so can't check with another key. Did you manage to find out what caused or how to stop it happening again. Thank you

[Adrian E]

A quick search of the Ross-tech wiki has confirmed my vague recollections of this issue:

http://wiki.ross-tech.com/wiki/index.php/00955

Basically in HP's case, if the key buttons have been pressed too many times whilst outside the receiving range of the car, then the rolling codes get out of sequence. Doing the manual sync by doing what you did basically resets the sync and explains why it's now working.

All it needs is, for example, small hands getting hold of the key and having fun pressing the buttons to lose the sync.

[HPsauce]

Thanks Adrian, that was my recollection too. Only problem is there's no way little fingers (or anything else) could repeatedly press the key between uses because of where it's kept, at least not that I can in any way dream up!
But yes, the manual process resets things, I now recall having to do that with a spare key years ago.

[spannerrash]

Well that's a nice timely thread. Was recently having the same problem. Changed the batteries which didn't make any difference but then opened the door with the key and started the car, now all OK.

I didn't do this with any real though process just wanted to be sure I could open and start the car the old fashioned way.

It's nice to have an understanding of what might be going on. Thanks all for sharing.