2014 V70 Authorities (Police) version brake wear light

[Naskinner]

Hi,
I have a 2014 V70 Authorities (Police) version.
It has a brake wear indicator LED immediately behind the steering wheel, which I understand is only on the Police versions.
Shortly after buying the car, this LED changed from green to amber, so I found some OEM front pads with the indicator lead. I changed the pads, which TBH didn't seem like they were even close to minimum thickness, but thought I might as well change them anyway.
Unfortunately, there was no change to the LED. Being a relatively minor issue, I have lived with it ever since.
I have VIDA & DICE, but no fault code shows, and I haven't found any reset in VIDA.

More recently I discovered that occasionally the LED would briefly change back to green before reverting to amber. Anyway, I managed to trace this to a dodgy terminal on the rear of the LED, so thinking this might resolve my issue, I sourced a replacement LED and installed that.
Unfortunately, the LED stubbornly remains amber, suggesting that the system does indeed believe the pads are worn when they are not.

Having replaced the LED, I now understand how it changes colour, it has a common negative terminal, a 'red' terminal and a 'green' terminal. If there is voltage on either of the 'colour' terminals, it shows that colour, but if there is voltage on both, it shows amber. I assume there is some control circuitry somewhere that controls which terminal the voltage is fed to, but without physically tracking the wiring behind the dash, I wouldn't know where to find it.

I have the wiring diagram for the 2014 V70, but this does not include the Police version, and shows no brake wear circuitry, and my search abilities have failed me in finding the relevant amendment for the wiring diagram, if one even exists.

To assist me in tracing this annoying (but minor) issue, does anyone have either a copy of the relevant wiring diagram amendment, or some knowledge to assist me in fault tracing, before I have to start trying to trace the wiring behind the dash..?

Thanks