Hello,

We've got a 2014 Suburban LTZ and when we were riding in a rather hilly area of New York recently, the vehicle would suddenly rev the engine as though it were automatically downshifting when going down long hills with the brake mildly applied. There wasn't a full loss of control per se - it was more of the sudden surprise of feeling a sudden engine rev.

Is that normal? I haven't found any references online, but I'm wondering if the truck automatically downshifts to prevent the brakes from overheating due to the weight of a vehicle?

Thanks,

Scott

 

The feature that you uncovered on your Suburban is called Powertrain Grade Braking. It is a feature that uses the engine and transmission to help slow down the vehicle on hills. It is nice feature to have on a Suburban and will help to keep your brakes from over heating on a steep grade and provides more control on steep grades.

There is additional information on this feature in your owners manual on page 9-31, under Grade braking normal mode.