AutoHex II is a powerful tool to program BMW keys in all key lost situations. But in the case of BMW E70/E71 X5 and X6, there will be different scenarios that arise.
There are two types of EGS that come with E70 and E71, one with 8hp EGS and the other with 6hp EGS and both the TCUs have EWS is enabled (EGS has a security enabled). In the case of 8hp EGS, those have a long ISN of 16 bytes and this ISN will be the same as the CAS and DME/DDE of the car.
To program all keys lost for this 8hp E70 and E71 it is possible to read DME ISN and use that 16 bytes DME/DDE ISN to program key from key programming option 4.
In the other case where 6hp EGS equipped in BMW E70/E71 and the included DME/DDE has a long ISN, in this situation also key programming required the same DME/DDE long ISN to break CAS security and program key from key learning option 4.
BMW E70/E71 Special Case
For the E70 and E71 with 6hp EGS and those have DME ISN as short as 2 bytes (4 digits), EGS also has the 4 bytes ISN(8 digits), in this case, the DME ISN is a part of the EGS ISN, CAS has EGS ISN stored and synced to make the car working smooth.
For all of the cases in BMW key programming, ISN in CAS is used to break its security to program key and we are getting that ISN from DME/DDE as it is available to read. So, in 6hp E70 and E71 with DME short ISN, CAS has DME and EGS ISN stored and EGS itself also has this ISN synced inside.
To break security in CAS the DME/DDE ISN alone is not possible to program BMW key instead of that it requires EGS ISN too.
To program key, you need to read DME ISN from ISN manager option 1, there will be 2 bytes ISN. Then you have to proceed to ISN manager option 3 to read EGS ISN with AutoHex.
From ISN manager option 3 software will ask if you want to sync EGS with CAS so click no as we don’t need to sync but only need ISN inside EGS. Check the EGS ISN with DME as follows, that will be the ISN inside CAS and will be used to program the key.
It is important to use EGS ISN followed by DME ISN to program the key, both will make up to the 4 bytes ISN and the key can be programmed from key learning option 4 for all key lost situations.
Also, all other procedures to program the key once have ISN is as like other E series models. It is possible to prepare a blank key with HexTag/HexProg or a key with the key file to program to the CAS.
Please check the below video for a better understanding of programming keys E70 and E71 all keys lost with short ISN in DME.
Below video explains how Autohex II works in this case.