deadstock

1st off let me say I'm a newb. This is the first 4wd I've ever owned. I got a 2014 4 runner limited recently. We just got hit with a snow storm and our roads are icey. At a stop sign I put the tranny in Neutral then activated the 4wd lo to go up a hill. As I stared to accelerate and turn the 4wd light started blinking and beeping then came the grinding noise. I immediately stopped put the tranny back into neutral then back to the standard AWD mode. I was only going about 8 mph. I then drove around for about 5 miles to make sure the 4 Runner drove ok. I activated the 4wd lo again and drove up an icy hill and didn't hear the grinding noise. Anybody know if I caused any damage? It appears as if the 4wd lo was completly activated?