How to read ISN Code of BMW EDC16c35


ISN is not a software, but rather it is the immobilizer key code that the EWS or CAS module (the immobilizer security module). Newer cars’ ISNs use a starting code that is stored in the DME (or DDE if a diesel car) and then change the code (rolling code) with each successful engine start. The EWS/CAS and DME/DDE stored ISN must match, or else the car will not start. There is no BMW software that does anything with the ISN, besides the first time DME to EWS/CAS pairing (on virgin DME or virgin EWS)

There are aftermarket (non-BMW) software that help with ISN identification and maybe even modification, but this is done after reading a module’s EEPROM or flash memory. This requires very intensive knowledge of electronics, and some expensive interfaces.

Some ECUs have the ISN in a OTP section (one time programming) of the memory (ex: MSD80 DME of the 335i), so essentially that ECU is married for life, you cannot edit anything to that ISN. There are very expensive interfaces that can edit the EWS or CAS to match the used DME, but this is besides the point.

Those interfaces include genuine AVDI, FVDI, or Autohex.

And if you are talking about a little piece of software called “BMW ISN”, this is an aftermarket program that goes together with yet another expensive interface, BMW Explorer or Autohex ii, that can edit the ISN in the EWS or CAS. Mostly useless without proper interfaces and tools.

How to read ISN of EDC16c35 (for example in encrypted CAS3 + when all keys are lost)? An increasing number of locksmiths verified CGDI Yes, Autohex Yes, VVDI No.


Autohex: Yes, but not on bench

Tried ISN extraction via ON-BENCH, didn’t work

Finally succeeded with the following steps:
-> copy content of 96540 eeprom of original-ECU to donor-ecu
-> coded the donor-ecu to the car
-> updated the software of the donor-ecu
-> EWS alignment

CGDI BMW programmer: Yes

Oh I surprised, I can read ISN of EDC16c35 right with CGDI and AVDI but not change.


Open CGDI software -> select “BMW ISN Read Write” -> select ECU type -> click on “Read DME ISN” and then after it succeed, click on “Write DME ISN”.

It’s nice feature is it come with wiring diagram.

Good to know:

CGDI BMW programmer wins in ISN reading /writing for a wide range of DME. And it is available with individual BMW ISN reading authorization.





Xhorse VVD2: Failed

I bought Xhorse VVDI2 new, can‘t read ISN of EDC16c35 . Not on bench not in car.

I think VVDI II cannot read 2 bytes ISN.

Path: open VVDI2 Quick Start -> BMW -> Key Learn -> ECU/CAS ISN -> Type E-Series ISN -EDC16xx.

No matter what you select “Diagram”, “Read ECU information”, “Read ECU ISN”, it will pop up not supported yet or failed.   But software prompts it will add this type in the feature.






Hope it helps!

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