Quote:
Originally Posted by NZ_M3
Huh? Really? How did he by-pass the EWS 3.3 rolling code that gets burned into the MSS54 DME once when you first align the two?? As far as I know that can't be done on a stock DME (which is why you always have to pair the EWS with a DME).
Also it's not the DME that sees the key it's the EWS - it has a coded table for 10 keys (4 pre-loaded from the factory), and the loop merely powers up the transponder inside the key which sends the EWS its unique key code. The EWS then compares this to the coded table to see if the key is authorised or barred - if authorised, it releases the relay on the starter and then sends the ISN signal to the DME for start up procedure - even if it sends this, the DME still compares the rolling coded table (some 200 of them) to the one burned into its once only memory - if the EWS's rolling code table isn't matched to the DME , the car doesn't start (this is the immobliser portion within the DME) - (to stop people swapping out precoded EWS modules in cars that are paired to stolen keys.)
This is why when you order a new EWS from BMW they code it to exactly the same as the one in your car - so the rolling code table matches up. Which is also why when you've used all 10 keys pre-stored in the EWS you have no choice but to buy a new DME and EWS and start the alignment procedure from scratch.
Your friend must be fairly smart to be able to crack into the rolling code table and wipe it from the start up procedure ... as far as I know that can only be done on EWS 1, 2 but not 3.
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Couldn't have put it better myself Tom.
