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# PI0961C.
SERVICE HIGH VOLTAGE CHARGING SYSTEM Message Displayed on Driver Information Center (DIC),
Hybrid/EV Charging System Disabled, DTCs Set, Revised HV Battery Surge Tank Coolant Fill Level