What are these two things?

[johnsimcox]

VAG docs describe it as infra-red temperature and sunlight penetration sensor ...

Given its location not sure how much sunlight it actually sees!

[gupsterg]

There is a sunlight penetration photosensor ( G107 ) located on dash near main defroster vent.

Why they have one also on the A/C control unit also I .

All it states is "Determines the temperature and sunlight penetration on the operating unit. If the infrared sensor is concealed or contaminated, it can no longer supply correct measured values and the air conditioner will not be regulated properly".

If sensor fail it states "Combined with operating unit as one component, cannot be renewed separately".

[robes401]

Thanks for the useful info. Seems strange to me that there would be a temp sensor in the middle when each side is independently controlled, but seems to work ok!

[gupsterg]

There are 4 temps sensors in the a/c ducting for front dash vents and footwells, basic & deluxe a/c unit.

There are also 4 temps sensors in the a/c ducting 2 for the rear console vents and 2 for the rear footwell vents these are only on the deluxe unit.

[ukgroucho]

... and you can actually see this in action on the 4 zone AC if you bring the fan settings up on the MMI. On a day when you are driving with hot sunshine on one side of teh car and not the other you will see that the fan(s) on that side of the car are turned up a notch or two compared with the other side.