Audi A4 2015 TFSI/Auto cold start stalling issue

[Davej146]

Hi.  I seem to have an issue when starting the car from cold.

The car starts fine from cold but after around 30-60 secs, it starts vibrating/shuddering and the engine stalls.
A message comes up stating: start/stop system fault.  Function unavailable. No other errors or fault codes come up.

I wait about 1 minute and start up the car again.  Sometimes it starts fine from the second attempt and this time no vibrating/shuddering or stalling.
Sometimes it takes 2 or 3 further attempts to start the car eventually without stalling but then it runs fine.

The strange thing is that it only does this at cold start.  The car runs fine for the rest of the day with several engine starts without stalling or vibrating. Also the start/stop system works fine for the rest of the day.  This has happened at the current time which is during summer and not at cold weather conditions.

I have bought a new battery as the battery was a bit old but the problem persisted even after installing a new battery.

Any help in identifying the cause of this issue would be appreciated.

[Steve Q]

This link might help: 

https://www.audiworld.com/forums/a4-b8-platform-discussion-128/random-dying-cold-start-3068600/

[cliffcoggin]

1 hour ago, Davej146 said:

 

I have bought a new battery as the battery was a bit old but the problem persisted even after installing a new battery.

 

Did you have the new battery coded to the car? It won't work properly until you do.