GMC 2009 Sierra 1500 Crew Cab Owner's Manual page 457

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.
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.
2. If you have a vehicle with a diesel engine with 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, use the battery that
is closer to the starter -- this will reduce electrical
resistance. This is located on the passenger side,
in the rear of the engine compartment.
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 an unwanted
ground connection. 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 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 the lamps that are not needed.
This will avoid sparks and help save both batteries.
And it could save the radio!
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