GMC 2015 Sierra Denali Owner's Manual page 361

10-90 Vehicle Care
battery. Use a remote
positive (+) terminal if the
vehicle has one.
9. Connect the black negative ( )
cable to the negative ( ) terminal
of the good battery. Use a
remote negative ( ) terminal if
the vehicle has one.
Do not let the other end touch
anything until the next step.
10. Connect the other end of the
negative ( ) cable.
5.3L and 6.2L
To the metal bracket that is
bolted to the engine and
supports the resonator, on
the vehicle with the dead
battery.
6.0L
To the generator bracket, on
the vehicle with the dead
battery.