Chevrolet Malibu 2003 Manual page 74

Remote Trunk Release
If your vehicle has the remote trunk release lockout
feature, make sure it is not activated. Also, the remote
trunk release will only work when either the ignition
is off, or with the ignition in ON while either the parking
brake is engaged or the vehicle speed is less than
2 mph (3 km/h).
2-12
Press the remote trunk
release button, located on
the lower left side of
the instrument panel, to
release the trunk lid.
Remote Trunk Release Lockout
Your vehicle may have a lockout feature. The switch is
located on the inside of the trunk lid, mounted on
the trunk lid latch.
To turn the lockout on, slide the switch all the way to
the left (ON). To turn the lockout off, slide the switch all
the way to the right (OFF).
When the lockout is on, the remote trunk release switch
on the instrument panel will not release the trunk lid.
However, the trunk lid can still be opened with the key,
but not with the remote keyless entry transmitter.