The 170 FSC was introduced in a later NBT firmware update to combat theft of these desirable head units. If a used NBT2 or MGU head unit is retrofitted to another vehicle it will lockout with a VIN mismatch.
The unit cannot then be reactivated until a 170 FSC is released for the head units VIN number. BMW will not release a 170 FSC unless the VIN in question was fitted with this NBT / MGU head unit from new, thus reducing their desirability from theft.
There is a very innocent way you can be faced with this issue. If your vehicle has had a software update out of the BMW network you will very likely be facing this problem. The newer firmware contains the need for the 170 FSC to activate, your car however doesn’t have this FSC loaded as it was not invented when your car was new. This unit will then shut down the nav function, giving you a loading screen like the unit pictured below.
These units can be reactivated with a complete FSC set.
We do not support the retrofitting of these units. Sadly, if that is why your here, we cannot help. We only offer this service for vehicles that have been factory fitted with this equipment and have suffered the lockout.