GMC 2012 Sierra Denali Owner's Manual page 422

10-84 Vehicle Care
Notice: Only use a vehicle that
has a 12-volt system with a
negative ground for jump
starting. If the other vehicle does
not have a 12-volt system with a
negative ground, both vehicles
can be damaged.
3. Get the vehicles close enough
so the jumper cables can reach,
but be sure the vehicles are not
touching each other. If they are,
it could cause a ground
connection you do not want. You
would not be able to start your
vehicle, and the bad grounding
could damage the electrical
systems.
To avoid the possibility of the
vehicles rolling, set the parking
brake firmly on both vehicles
involved in the jump start
procedure. Put the automatic
transmission in P (Park) or a
manual transmission in Neutral
before setting the parking brake.
If you have a four-wheel-drive
vehicle, be sure the transfer
case is in a drive gear, not in
Neutral.
Notice: If any accessories are left
on or plugged in during the jump
starting procedure, they could be
damaged. The repairs would not
be covered by the vehicle
warranty. Whenever possible,
turn off or unplug all accessories
on either vehicle when jump
starting the vehicle.
4. Turn off the ignition on both
vehicles. Unplug unnecessary
accessories plugged into the
accessory power outlets. Turn
off the radio and all lamps that
are not needed. This avoids
sparks and helps save both
batteries. And it could save the
radio.
5. Open the hood on the other
vehicle and locate the
positive (+) and negative ( )
terminal locations on that
vehicle.
The positive (+) terminal is
located under a red plastic cover
at the positive battery post. To
uncover the positive (+) terminal,
open the red plastic cover.
If your vehicle has a gasoline
engine, the remote negative ( )
terminal is a stud located on the
right front of the engine, where
the negative battery cable
attaches.