Can I swap the mirror/UEM AND the push button start? 2008 V70 3.2

[Pedey]

Hi everyone,

I'm new to Volvo ownership and have run into a problem with the 2008 V70 3.2 JDM import I just bought.

One of my major issues is that the car sometimes will not unlock with either of the FOBs, which I've just replaced both batteries for. There's no rhyme or reason as to when it will happen, and it's a real problem as the manual key doesn't unlock the door. It turns as it should, but nothing unlocks, so I'm unable to get inside when this happens. I can walk away and then try again a few hours later and it may or may not work.

I've done some research and this appears to be a problem with the UEM control unit in the mirror of the car. I realise it's coded to my fobs, so if I get a mirror from a wrecker it won't work. But, if I also got the fobs from that same wrecked car, as well as the unit behind the push button start (where you slot the key into), changed it all over, would I then be able to use the car fine, as everything that is tied to the fob/fobs would be changed?

Is my logic solid here or way off? Would really appreciate any help. Thank you.

Also, has the manual key problem happened to anyone else? Everything feels as it should, but the lock does nothing, and the car's battery is fine.