Pontiac Montana SV6 2007 Owner's Manual page 116

Sliding Door Lock
116
CAUTION:
{
If your vehicle is facing downward on a
steep grade (15 percent or more), the door
may not stay open and could slam shut,
possibly injuring someone. To make sure
the door does not slam shut be sure to
hold it open until everyone is clear of the
door, and only then allow it to slowly close.