Immobiliser rolling codes

[IanW]

A discussion with a colleague has raised an interesting point.

Given that the keyfob radio code changes on each keypress, has anyone had it fail to unlock/mobilise the car due to the buttons being pressed too many times while out of range?

The suggestion is that only the next keyfob code, plus the following 10 or so will actually be recognised. So pressing the button too many times while out of range will result in a useless key.

Now personally, I think this is an urban myth - a bit like using the spare keys via a mobile phone etc. But before I perform my experiment this evening, I thought I'd check on the collective wisdom. And get an estimate for recoding the immobiliser to the key...

Ian.

 

[jaymanek]

no dont believe it at all..

 

[alexander patie]

i think the car accepts any one of the next 100 or so codes, so you can press the key 99 times when out of range and it will still unlock. every time the car sees the key it will synchronise, so this is not a common problem. resyncing keys is not too hard, i did an ml today - press and hold lock button whilst pressing unlock 5x times, it worked.