BMW Multi Tool failed at the security access

I have done a few 2006- 2008 BMW 328’s with the Xhorse BMW Multi Tool v4.9, I tried to do a 2010 328i today and it failed at the security access. I have now updated to v7.7 and the hardware is now at 1.0.6. 2010 328i is CAS3+.

A BMW expert explained: whether the car has been into the dealer recently or not, all BMW’s that go into the dealer are having the CAS unit updated to stop the recent theft issues, that’s why your BMW multitool v7.7 is failing at the security access, if it’s been in to the dealer then it’s not possible to make a key obd, unless you downgrade the CAS unit.

Because BMW multi tool OBD2 key programmer user manual is not clearly, then I haven’t idea on how to go on next step, at that time, I got a complete answer from a very experienced technician, he said:


Add key OBD:

CAS3+ encrypt version -> no need to update CAS (no need for key cycling)

CAS ISTAP4x version -> need to update CAS (no need for key cycling)

Lost key OBD:

CAS3+ encrypt version -> no need to update CAS (need to cycle key UPTO 16 times)

CAS ISTAP4x version -> need to update CAS (need to cycle key UPTO 64 times)

 Add key dump method (lost or working key):

CAS3+ encrypt version -> need to write back to CAS (needs either -working key / known ISN / ECU dump / or cycle UPTO 16 times)

CAS ISTAP4x version -> no need to write back to CAS (needs either -working key / known ISN / ECU dump / or cycle UPTO 64 times)

So the 64 cycle is really to save you having to downgrade the CAS but you still need to manually read the CAS for this option. For me this is still the best way as there’s no way I would downgrade the CAS (unless you made it very clear what this meant to the client)

BMW Multi Tool +CAS PLUG

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