2008 legacy gt trunk lid keeps popping when putting key in ignition.
 

Bought an 08 legacy gt recently. Weird thing keeps happening.

When I unlock the car( being sure of the button I click) opens the car. I get in, put key in ignition and the trunk pops open automatically. Thought I was bumping it but keeps happening. No idea why? I google searched it with no luck.

Anyone familiar with this? It doesn't happen every time but more than half the time it seems.

Seems to actually happen when the door closes. The hazards blink once and then the trunk pops.

Doesn't happen every time. Been trying to see if anything in particular causes it but seems to be no pattern. Just happens about 75% of the time.

Does it even happen any other time? Have you ever come out to find it already popped?

Do you know where the car came from? Where the previous owner lived?

It's not every other time. Probably more like 75% of the time or more. No I haven't found it already popped ever. Only when I unlock the car and get in. I opened up the key and everything looks fine inside.

Car came from near me in MA. Don't know the previous owner.

Now it started setting off the panic alarm thing now. Once I get in car the lights start flashing and the horn starts beeping.. Wtf!

My first thought was maybe the car had been in water, but with both the trunk popping and now the alarm going off it seems more like a problem with the key than the car.
Do you have a valet key? If not, take the battery for the remote out of the key or the whole remote piece (I assume the transponder is built into the plastic housing, not the remote itself) and see if that helps.

Maybe you just need to replace the battery, they can do weird things when they drain.

I'm kind of thinking may this is what you need to do...^

How old is the cars battery BTW ?

Ok cool. I'll try replacing the battery. I did take the key apart once this started happening and everything looked good inside. No gunk or anything like that

The car battery I just replaced day after I bought the car since it lost its charge really quickly and appeared to be original battery. Had a lot of corrosion on it as well.
Could replacing the battery some how blow a fuse that could do these kinds of things?

Oh also unfortunately when I bought the car there was only 1 key included.

I just unlocked the door with just the key and not the remote. When I got in the car it popped the trunk.. Would think its not the remote then if I didn't even push a button.

look under dash for aftermarket wiring for remote starter, possibility its wired into trunk release?

I'll take a look. Thanks! Seems the door opening triggers it.

if thats the case you could probably un-plug the actuator in the door and just manually open it with lock cylinder.. dont quote me on that though Ive never tried it

Can't see what else would trigger it. Happened when I manually unlocked doors with a key and not remote so don't see how the remote would be doing it. Could be a light triggering it that turns on as well when the door opens.