Push the turn signal lever away from you and release, to turn the high beams on. To return to low beams, push the lever again or pull it toward you and release.

This indicator light turns on in the instrument cluster when the high-beam headlamps are on.
Exterior Lamp Controls
Flash-to-Pass#PI0574A: Missing OnStar Owner Kit Integration in Vehicle Owner Manual - (May 28, 2013)
Subject:Missing OnStar® Owner Kit Integration in Vehicle Owner ManualModels: 2012-2014 GM Passenger Cars and Light Duty Trucks This bulletin is being revised to include the 2013-2014 model year vehicles, updatethe covered models and the Recommendation/Instructions section. Please discard PI057 ...