Hey calvintys...i had a hicas problem once...same car as you, but when the hicas lighted up the car would then swerve left or right...not sure what was going on there but brought it to my mechanic n they fixed it...cost quite a bit though...said was some control arm thing.
have a look on the net...there are plenty of places which teach you to put the car into diagnostics which will then flash hicas error codes if you have any errors with the system.
hmm...not sure on that GRID thing. i understand that the 4wd light will only come on if there is a problem with it, but i think if your torque split controller is installed properly then the system shouldn't think there's an error, hence no light??
also, the attessa system is linked with the abs system which could indicate your torque controller is not set up properly, thus causing the brakes to bite??