I have a 2006 V70 and the only problem right now is the rear door won't lock/unlock. Drivers door opens with one click of the remote and the front and back doors open with a second click of the remote (that's how its setup). Passenger cabin doors lock by remote. However, the tailgate doesn't lock or unlock by the remote.

The alarm is set off when the rear door is opened (despite it not being locked) and the interior lights come on when the rear door is opened

I've searched here and find a few possible causes but want to start with the basics - fuses and relays. I've been looking for the door lock relays and can't find them. The wiring diagrams I've found as well as relay location guides on the internet show them in the rear drivers side fuse box but in my car there seem to only be fuses in that location. The relays in the engine bay don't seem to be related. Also some internet searching seems to indicate the wiring and relays/location differ somewhat by year?

So, assuming that relays are a thing to check as a basic troubleshooting, where are they located in my car?! I've checked all the fuses I can find in engine bay and rear drivers side. Once relays and fuses are ruled out, I'm guessing tailgate wiring and the lock latch mechanism itself would be the next steps?

Better yet, any other suggestions on what the problem might be? I do have VIDA but haven't tried that yet.