Thanks for the info.

Quick update - same issue occurred again today. I had the laptop on me so I cleared the codes, but interestingly the DDE was completely unresponsive. I locked the car and left it for ten mins and came back and it was back online. I cleared the codes and away I went.

Tbh I was sceptical the CAS could cause this condition based on the feedback from others here and reading up on how the modules interact, but I was hoping on the off chance it would fix it.

So far, new battery and new CAS. Issue is still there. It appears to only surface on long drives however. Short drives don’t trigger the issue.

ISTA thinks the DDE is fine and once the errors are cleared, there are no errors or issues until the next time it stalls. Could the DDE be faulty?

I’m bringing it back to the dealer first thing in the morning. Needless to say, I’m not impressed.