After my earlier plea for help, I went over to see @varooom who had access to an earlier version on VCDS and also ODIS.
Sadly the VCDS couldn’t find Hex A9, so we plugged in the ODIS into the OBD port and computer and went from there.
Car ignition was on, and bonnet open during this process.
It was a bit like a needle in a haystack, with very little information on YouTube or the web.
After searching through probably 1,000 different modules/entries on the screen, eventually we found under 0001 Engine Electronics a submenu with 00A9, the dreaded Sound Actuator. This should be photo#1
clicking on that took is to the second picture, which showed the volume of the actuator as 100. We (he) then changed that value to “0” (zero), clicked “apply”.
Then as per the third picture, you can see it has stored the current value as 0.
Shut the ODIS down and remove plug from OBD port
Turned ignition off, shut the bonnet, shut and locked the car for a minute.
unlocked the car and started up.
And silence (from the actutor) ensues.
As all you have done is turn down the volume, no other faults are thrown. (Disconnecting the unit physically reportedly throws other faults up, and removing the fuse also stops other stuff working)
Anyhow, that’s how it was done, and hopefully this information will save other people a lot of time trying to find where 00A9 is buried on ODIS
Oh, just to add, running the diagnostics does chew through the car battery, so make sure you have a jump start pack or can plug the car in to something g like a Ctek charger/conditioner while running the diagnostics. And make sure you have turned the heated seat off too as that really seems to eat the battery 🤦🏼
And big thanks to my new hero, @varooom