GMC 2011 Sierra Denali Owner's Manual page 427

Notice: Ignoring these steps
could result in costly damage to
the vehicle that would not be
covered by the warranty.
Trying to start the vehicle by
pushing or pulling it will not
work, and it could damage the
vehicle.
1. Check the other vehicle. It must
have a 12-volt battery with a
negative ground system.
2. If you have a vehicle with a
diesel engine and two batteries,
you should know before you
begin that, especially in cold
weather, you may not be able to
get enough power from a single
battery in another vehicle to start
your diesel engine. If your
vehicle has more than one
battery, using the battery that is
closer to the starter will reduce
electrical resistance. This is
located on the passenger side,
in the rear of the engine
compartment.
Notice: If the other vehicle's
system is not a 12-volt system
with a negative ground, both
vehicles can be damaged. Only
use vehicles with 12-volt systems
with negative grounds to jump
start your vehicle.
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.
Vehicle Care
If you have a four-wheel-drive
vehicle, be sure the transfer
case is in a drive gear, not in
Neutral.
Notice: If you leave the radio or
other accessories on during the
jump starting procedure, they
could be damaged. The repairs
would not be covered by the
warranty. Always turn off the
radio and other accessories when
jump starting the vehicle.
4. Turn off the ignition on both
vehicles. Unplug unnecessary
accessories plugged into the
cigarette lighter or 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.
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