- its the van detecting paracitic power drain from the starter battery.
it uses 061 - battery monitor shunt to meter out power, (bolted to the NEG battery post)
when the van goes to sleep its still monitoring the power draw . . . the spec ia around 50mA . . while sleeping
above this 50mA it will trigger the code . . ( so 150mA or 200mA from a USB charger or dashcam will trigger it)
so leaving things plugged into a 24/7 power socket will draw power and trigger the warning.
I've left OBD2 units plugged in (like Carista or VCDS) - that will also trigger the code over night.
very cleaver stuff.
the same module meters out power from a mains charger too . . . which is why VW say don't connect anything to the battery NEG terminal - use another chassis point ( thats so you dont bridge out the sensor and effect the data collection)
