Hi, when I jumped in my car this evening to drive home, I noticed the climate buttons were not on and it rebooted about 2mins later and I noticed the stop/start function button was now missing? Anyone else seen this. 
 

it must have been a software update or something.

48 minutes ago, skiduk said:

Hi, when I jumped in my car this evening to drive home, I noticed the climate buttons were not on and it rebooted about 2mins later and I noticed the stop/start function button was now missing? Anyone else seen this. 
 

it must have been a software update or something.

I doubt it. You'd need to scan the car with VCDS to see any logged DTC error codes. More like battery could be on the way out. Modern cars are very susceptible to a drop in battery voltage fluctuation.

56 minutes ago, spartacus 68 said:

I doubt it. You'd need to scan the car with VCDS to see any logged DTC error codes. More like battery could be on the way out. Modern cars are very susceptible to a drop in battery voltage fluctuation.

But why would the button disappear surely the stop/start function would just not kick in if the battery was low on power.

I’m just guessing. Is there is physically button on A6 C8 or is it built into virtual cockpit touch-screen, etc?
 

Similar car but with 48v hybrid battery. We never did find out the reason why? Is yours standard 12v?

 

it’s built into the display, no physical button.

Edited February 9Feb 9 by skiduk

Just so I’m not going mad, the button was there, also I have now noticed the lane departure button is also missing.

I’ve read reports of software glitches, from everything to do with camera and radar, through to not locking car properly. You can guess, but the only way to really see what’s going on is to get the car scanned. Car is 2021,  so it would be unusual for battery to be on the way out, however VCDS captures battery voltage during scan, plus reveals logged DTC errors. At this time of the year, batteries do take a beating with lights, heated seats, air conditioning, so anything is possible.

Even a cheap multimeter, straight onto the battery will give you some indication of health. You should be in region of 12.4 - 12.6v (car not started), rising to potentially 14.7v under load. If it is battery, install like for like AGM battery (remember to vent), and code in, then clear codes.

Edited February 10Feb 10 by spartacus 68

No issues with the battery stop start is working to well turning the engine off at every light, junction and roundabout. 

Must have been a software issue, this morning when the car started the button had returned after the system went through an initialisation process.

i did email customer services to see if it was a known issue, but I know their response will be send the vehicle in for diagnostics for a fee.

anyway it’s sorted for now. 

Ants.

False warnings and error messages are typical of a dying battery. It would be as well to get the battery professionally tested.