Where is alarm-siren module located on 20014 XC70?

I was expecting to find the alarm module behind the passenger side front wheel arch. It's not located there. My expectation was based on going to the junkyard and pulling said module off a 2004 S60. The MY is 2004....sorry for typo in headline.

If you're talking a 2004:

In the passenger side (right hand) front fender, behind the headlight assembly. If you search a bit here there is plenty of discussion, and even I believe a VADIS illustration of how to access. You can either remove the fender liner (requires drilling out rivets and dealing with a tamper proof bolt) or partially remove the bumper shell, remove a headlight assembly and fuss with a regular (but difficult to access) bolt.

If you mean 2014, this is the wrong sub-forum.

It's a 2004 XC70. And I started by peeling back the front pass. side wheel arch, and don't find the alarm module there. I was expecting it to be there, bc I had gone to the junkyard and removed an alarm module from a '04 S60, found inside the pass. wheel arch.

Someone on SwedeSpeed claims it's behind the front bumper. ???

I'm getting the "Alarm System Service Required" console message, which I take to be the backup battery in it failed. I just need to find the module.

I believe the photos attached to this posting make clear where the Anti-Theft Alarm Module is located:
https://volvoforums.com/forum/volvo-...working-73240/

On the S60, it's mounted to the outside of the engine compartment wall, whereas on the XC70, it's mounted directly above the windshield washer fluid tank.
On the S60, you don't have to completely remove the wheel arch to get at it -- you can peel it back without removing any rivets. On the XC70, the rivets and arch have to come out.

I'm pretty certain that it's in the same location as it was on my three Volvos...

You have to remove the entire fender liner, which means rivets, too.

It's under the fender, behind the headlight, forward of the wheel well and up high.

You'll have to dremel the security bolts, usually, and I just replaced them with regular 6mm bolts (I think that's the size...). No car thief is going to go through there to get at that alarm module on a 15 year old car. Think how hard it is for you with the front wheel removed...

Changed mine (MY2004) just last week and found it it where I expected to see it - on passenger side under fender liner mounted up high.

Re fender liner, I just drilled the five rivets towards the front, removed the 2 10mm plastic nuts and my able assistant held the liner back while I worked on it. To loosen the bolt, I used a chisel and a couple of taps with a hammer loosened it enough so that I could screw it out by hand.

It was a very simple job and took about 20 minutes in total.

I got to the siren module. The wheel arch front rivets have to come out, but my experience is that you can pry them out and reuse them....I used a nail puller tool to extract them. You can leave the rear rivets attached, and fold back the wheel arch enough to get the alarm module out.

The work on the alarm module was tedious but straightforward.

You want to start by disconnecting the battery, since the alarm system is one of the modules always ON.

After removing the module, I clamped the module to a bench, and used a hand mitre saw to cut the casing apart along the black and gray plastic seam. DO NOT let the saw penetrate the casing more than 1 mm deep....you have to respect the wires and components on the circuit board.
I replaced the original failed battery with a new 7.2 V rechargeable NiMH. It didn't quite fit in the casing, so I had to cut a hole in the rear of the casing for it to stick out. Note the (+ - ) polarity of the battery plug on the circuit board, and make sure the new battery goes in hooked up correctly.

When all put together, I used a bathtub sealant to close up the case watertight.

The steel cage that houses the alarm had to be cut slightly for my protruding battery pack.

Plugged back in, and the battery reconnected (ignition key in position II), I was happy that the "Alarm System Service Required" console message did not appear.
I believe it to be the case that this alarm module can have its internal 7.2 V battery replaced without the ECM ever knowing about it, so long as the car battery is disconnected during the procedure, and the same alarm circuit board goes back in. Fortunately, my circuit board was in good condition -- no corrosion from the old battery.

I found it easy to remove the front bumper then remove the passenger headlight assembly. You then have access to the siren module without dealing with the security screw. You will need a short 10mm wrench to remove the lower nut.