GMC Sierra Denali 2006 Owner's Manual page 323

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 your 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.
9. Connect the other end
of the negative (−)
cable to the remote
negative (−) terminal,
marked GND, on
the vehicle with the
dead battery.
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
5-43