The trunk on your 2005 sunfire will not latch How can it be fix?

It sounds like a problem with the remote, if you have one, stuck in the "open" position. Otherwise use an oil penetrant and work the latch manually until it returns to its normal position. Note: it could be stuck in the closed or shut position too, but less likely. Then you would need to try and get the latch itself open, even though the trunk lid is already open.