New 2016 GMC Yukon Denali LDW (Lane Departure Warning) not vibrating the seat like it should. Also Known as the Haptic Seat. I am getting the run around from GM and dealers as to weather or not this vehicle is equipped with this feature.

Have them run a build sheet for you showing all the RPO codes. Then, do some on line research to see which RPO code is associated with Haptic seat.

From what I gather on my brief stroll on the interwebbs, it is part of the "Driver Alert Package", RPO Y65.

So far that seems to be what I have found for the 2014/2015 model year, but I found nothing associated with the 2016 model year. Hopefully they didn't change everything around just to be annoying.

As was said though, dealership is the best place to go for the most reliable info.

Then again, I went on the internet, and I found this:

Model Information - Online Ordering Guide

Seems like, if I am reading that right, it'* optional on SLE, and standard on SLT and Denali