My 2015 Sierra Denali has grade braking. When it senses I am using the brakes the transmission automatically selects a lower gear etc. So look in grade braking, it should be a standard feature on the Silverado.
2016 models
Re: Transmission, 6-speed automatic, electronically controlled with overdrive and tow/haul mode. Includes Cruise Grade Braking and Powertrain Grade Braking.
1LZ
Requires Double Cab model and (L83) 5.3L EcoTec3 V8 engine. Requires Crew cab model without (NHT) Max Trailering Package or (L86) 6.2L EcoTec3 V8 engine.
2LZ
Requires Double Cab model and (L83) 5.3L EcoTec3 V8 engine.
