BMW Explorer Write Keys CAS3+ Software Version above ISTA 43

E-series key programming with BMW E/F Scanner (BMW Explorer) when CAS updated by ISTA43 or up

Ignition keys cannot be written via OBD socket into CAS modules programmed by ISTA ver.43 or higher
Key writing is only possible having at least one working key or knowing ISN code (DME secret key) of this CAS.
You must read CAS3+ eeprom with help of any suitable reader (eg. Xprog,Rosfar etc.) and save it.
Upload saved eeprom file into built-in calculator, which can be found in Extra options menu of main window.


BMW Explorer will show message about encrypted CAS or not.(Not of all of CAS types can be autodetected)
Tick CAS3+ box


Attention!!! Read text below carefully!!!!
In case you have encrypted eeprom,you must use Hitag-2 programmer to read available working key.
Put key into Hitag-2 and read key ID
Then find Secret key strings in eeprom against this key ID. Write crypto low (8 characters) and crypto high (4 characters) values into Hitag-2 programmer (Crypto key & Serial number chapter of Hitag-2) and press Read ALL TM button.
If crypto low and crypto high entered are correct you will get key password in the 4-th row of transponder memory menu in Hitag.
Write 6 characters of key password into calculator (First byte C8 not need to be entered into calculator !!!! Enter only six characters after C8 ). Write key ID into ID field. Tick “From Key” box.

(TAKE key ID and password from Hitag-2 only!!!!…Not from eeprom!!!)

(Also you can decrypt eeprom by known ISN (EWS4_SK). Tick “from ISN” box, enter ISN and press DECRYPT


Make *.bek file using Hitag-2 and upload it into calculator.



Save and write EEprom back to the CAS with programmer and start your car.

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