Sorry, the NHTSA has not posted this TSB document yet.
You can still get the detailed info from Chevrolet for this TSB. Call your local Chevrolet dealer's service department & ask for a copy of TSB# 17-NA-319.
Diagnostic Tips for Loss Of Brakes, Brake Pedal Going To Floor, Brake Pedal Hard, Brake Pedal Mushy, Possible Service Brake Assist and/or Service Stabilitrak Lights Illuminated
Condition
Some customers may comment on the brake pedal going to the floor, brake pedal hard, brake pedal mushy, or possible Service Brake Assist and/or Service Stabilitrak lights illuminated