A4 Avant Black Ed 2015 B8.5 - No hill start, cruise control or auto start stop which occurred same day

[uwonbidvd]

Afternoon all, first post here and haven't really needed to look into any issues with my Audi in the 4 years I've had it, but have a bit of an odd one and looking for any advice on how to progress this if possible, so I ideally can pinpoint or narrow where to look without slinging cash at it repeatedly

I'll say this up front as no idea if this could impact anything, but these issues 'seemed' to have coincided, or certainly very closely, with using an eBay bought ODB2 scanner to try and self-diagnose an A/C issue. It's probably unrelated, but thought I'd mention it - I didn't try to change anything, just read the error codes, FWIW. Anyway, the following day, I noticed that hill start, CC and auto start stop were all broken, and also the 'change gear' notification on the dash. They were all working the day before. I took the car to the local VAG specialist, and they said the diagnostics showed the battery health was below 80% and they tried to give it a charge, but it wouldn't take. This was why those features turned off. It would require a new battery and reprogramming the features after clearing low voltage codes. The battery has since been replaced (I did check and it was not long for this world), but none of these features started to work again as I had expected.

The current thinking from the garage is that there is a faulty clutch sensor, which is apparently related to hill start, auto start stop and CC (not sure how it relates to the change gear notification though), but a bit of research I did to see if the clutch sensor can be replaced without having to replace the clutch cylinder it's connected to (which seems that it can be replaced independently) suggests my sensor "might" be OK, because that is what is required to know you've put your foot on the clutch to start the engine in the first place, so a duff sensor there would result in no engine start. It makes sense that something has failed and there is a chain reaction of failing dependent components.

I'm not second guessing the garage, just trying to hopefully minimise costs for additional repairs.

Thanks for reading and I appreciate any thoughts on this.


EDIT:

- The start stop has an error on the dash when the engine starts, stating that the function is unavailable
- The cruise control stick is effectively dead. No matter what position it is in or nudged up and down, button press etc, nothing changes on the dash to suggest input

[Crasher]

We need a full car scan, preferably using VCDS.