2006 v50 Key fob/alarm not working

[scav]

Hello, my key fob stopped working some time ago I am quite certain it was after I installed the amplifier. I tried changing the battery on the remote, but without any results. I can lock/unlock only the drivers door only with the key itself (not the remote), the alarm does not go off either. I can fully lock everything from the inside tho. Note that the key fob does not react to the car no matter which button is pressed.
After I took out the car battery for recharging and installing it again there was a message on the dash display saying alarm service required, although it disappeared. Any ideas?

[mf70]

And what flags does the car set in VIDA?

[oaktown]

Having exact same issue, including alarm service message a few times (not any more; battery had been removed) except I am using metal key to unlock door and alarm does go off (shuts off once key is inserted into ignition and turned to start engine). I was also having myriad electrical issues prior to this issue, most likely due to heavy rain. Brought it to local shop, they found 40+ error codes, all indicated high or low signal to ECM, cleared errors and kept indoors overnight, no other electrical issues since (it has also stopped raining for now too). No obvious interior water puddles (as I had last year due to sunroof drain plug or disconnected hose), but lower right (passenger) side windshield is fogged with condensation, indicating excess moisture in the area (near where the ECM is I believe).

Any solutions to the key fob issue greatly appreciated.