GMC 2009 Yukon XL Owner's Manual page 444

9. Connect the other end of the negative (−) cable to
the remote negative (−) terminal, on the vehicle with
the dead battery.
10. Now start the vehicle with the good battery and run
the engine for a while.
11. Try to start the vehicle that had the dead battery.
If it will not start after a few tries, it probably needs
service.
Notice: If the jumper cables are connected or
removed in the wrong order, electrical shorting may
occur and damage the vehicle. The repairs would not
be covered by the vehicle warranty. Always connect
and remove the jumper cables in the correct order,
making sure that the cables do not touch each other
or other metal.
5-48
Jumper Cable Removal
A. Heavy, Unpainted Metal Engine Part or Remote
Negative (−) Terminal
B. Good Battery or Remote Positive (+) and Remote
Negative (−) Terminals
C. Dead Battery or Remote Positive (+) Terminal