Battery Drain - don't want to hijack any other thread!

[JulianHicks]

As described elsewhere by Mechanico Lee, I think I have a battery drain problem caused by the external buttons on the door handles. Ive just started spotting errors with VCDS as below and I've [by chance] seen my Gateway and MMI panel come on briefly in the dark long after I've locked the car.

Lee, if you're reading this I'd be grateful for how you found the 'button drain problem' and more imporrtantly, what you did to fix it. But any other help would be greatly appreciated. I'm going mad with my car battery being flattened after only one day without use. [And I've CTEK charged it overnight beforehand only to see the voltage drop to 11.88V 36 hours later if the car's not used.]

VCDS scan looks like this for Right Rear Door:
================================================
Address 72: Door, Rear Right Labels: 4E0-910-802.lbl
Part No SW: 4E0 910 802 A HW: 4E0 959 802 C
Component: Türsteuer.HR BRM002 0060
Coding: 0026914
Shop #: WSC 02311 785 00200
VCID: 1E33B919C96614B1DD-804A

1 Fault Found:
02126 - Central Locking Button; Exterior Door Handle
008 - Implausible Signal
Freeze Frame:
Fault Status: 01101000
Fault Priority: 3
Fault Frequency: 0
Reset counter: 206
Mileage: 363584 km
Time Indication: 0
Date: 2017.01.05
Time: 14:07:20
=================================================
And reading the ECU measurement blocks I get:

Address 72: Door, Rear Right (4E0 910 802 A)

14:34:12 Group 001: General
00000000 Door Status
10 Button Status <--- This is the crucial flag as the 1 is the external button and it's on all the time!
1110 Voltages and Databus Status
12.72 V Voltage Supply

14:34:12 Group 002: Window Regulator Buttons (Local)
Not Oper. WR-Button (Local)

14:34:12 Group 003: Window Regulator
0.0 % Window Regulator Position
21.0 Window Regulator Motor Temperature
0011010 Window Regulator Status
Still Window Regulator Movement

Regards - Julian