Pontiac Torrent 2009 Owner's Manual page 90

Liftgate Operation with Loss of Power
The liftgate is equipped with an electric latch. If the
battery is disconnected or has low voltage, the liftgate
will not open.
2-12
To open the liftgate if
this happens, remove the
interior trim plug located at
the base of the liftgate from
inside the vehicle.
The liftgate can now be opened and closed manually.
You will need to use this procedure to open the
liftgate until the power is restored.
Use a tool to push the
service release lever
located on the latch until
you hear or feel the gate
release.