Diff lock question

[PornScooter]

I have searched and read tons of threads about the e-locker on the rear diff but I haven't been able to find exactly what I am looking for. I was hoping to find the answer in this forum.
My question is this, can the rear locker only be used in 4-Lo or does it work in 4-Hi as well? The reason I ask is this. If you read the users manual, it says that you should be in 4-Lo, but if you watch the video on the toyota website under the Trail Teams section which gives you tips on driving in snow, it appears that the driver is driving in 4-Hi (this is an assumption I know). Does the diff-lock icon light stay on constant when the diff is locked, or does blinking mean that it is engaged?
I apologize for the really n00b question, but I just need to know so I can satisfy myself that everything is working properly. Any input is appreciated!

[Kansas Law Dog]

The rear differential can be locked in only low range on the 4x4 versions of the FJ Cruiser. If you have a 2WD version, there is no low range, but if you ordered the vehicle with the $340 rear differential lock option, the vehicle will operate with a rear locker.

I'm not sure which video you are referring to, but it is probably TRAC (not to be confused with ATRAC) that senses a slipping rear wheel and pulses a braking action to the slipping wheel in order to transfer torque (power) through the open differential to the wheel with traction. TRAC is not programmed for the front wheels, but works in high range in either 2WD or 4WD.

ATRAC works in low range and senses a slipping wheel on the front axle as well as the rear axle. It is designed to sense a slipping wheel through either the front or rear open differential and brake pulse the slipping wheel. Note if you have the rear differential locked, the electronics would never sense a slipping wheel because by definition the differential is locked and both wheels turn at the same rpm.

[PornScooter]

Succinctly put. Much appreciated.