Starting tonight for the first time ever, for absolutely no reason, my 2009 xc70’s alarm has been sound off with no reason. No one out there by the car, animal or person.

I would like to mention we recently had major work done on the car at the dealership that involved many things including the battery being replaced, so I’m not sure if that triggered something. Since we got the car back, there is always a ‘warning’ indicating that the back hatch is open when it is not, it is fully closed and locked. Also, the exterior lights do not flash anymore when locking the car (as a result maybe?). I mention these things as they may be electronically related, but I have no idea.

What is going on?! I cannot deal with this. It’s 4:30am and I’ve been woken up 3 times since midnight with this audio assault. An easy fix? Cheap? I cannot afford another multi-thousand Volvo repair!

Could “possibly” be the notorious tailgate wiring issue. The harness tends to break down/short out where it passes through the LH tailgate hinge. That was the problem with my tailgate unlatched warning (along with a few other electrical issues like blown fuse for the fuel door, etc). It might also be causing your alarm to think someone is breaking into you rear windscreen. Maybe try pulling the fuse(s) that feed some those things that are tailgate-related or exercise the tailgate open and closed and see if that stops, or reduces, the alarm from going off.

If the lights don't flash the alarm isn't set? If so would that mean that the alarm horn can't go off? Make sure all of your doors shut properly. Exercise the door switches.