Non operable power liftgate

[TerminatorX5]

if the brain is dead, the GM has no idea that there is a power liftgate (option appears when module is present). On the newer (post i-Bus) cars, sometimes the GM needs to be pre-told about some modules in order to recognize them, it is done in the programming files. But, if you had the power liftgate from the factory, you can run your VIN on bmwvin.com and see if it was equipped so from the factory, regardless of wires or no wires (things might have been changed by previous owner, if you are not the original one)

[Rbmn9529]

There is no 40a fuse in slot 99, so I'm thinking there is no automatic liftgate