Cadillac 2009 XLR Owner's Manual page 360

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.
Jumper Cable Removal
A. Heavy, Unpainted Metal Engine Part
B. Good Battery
C. Dead Battery
6-40
To disconnect the jumper cables from both vehicles, do
the following:
1. Disconnect the black negative (−) cable from the
vehicle that had the dead battery.
2. Disconnect the black negative (−) cable from the
vehicle with the good battery.
3. Disconnect the red positive (+) cable from the
vehicle with the good battery.
4. Disconnect the red positive (+) cable from the other
vehicle.
Perform "Power Window Initialize" steps under Power
Windows on page 2-18, if the vehicle has experienced
power loss.