I've had a recurring Engine Start System error message on my dash (2013 A6 Avant 2.0 TDI) for a couple of years which when it first started Audi couldn't easily explain, so i've just lived with it, but now the message is displayed most of the time only going off for the odd day or so. VCDS shows the following, can anyone shine some light on what the problem might be, or do i need to bite the bullet again and book it in with Audi?

02764 - Access /Start Authorisation Switch (E408)
008 - Implausible Signal
Freeze Frame:
Fault status: 01101000
Fault Priority: 2
Fault Frequency: 1
Reset counter 152
Mileage: 117664 km
Time Indication: 0
Date 2020.07.10
Time 18:45:23

00576 – Terminal 15
008 - Implausible Signal
Freeze Frame:
Fault status: 01101000
Fault Priority: 3
Fault Frequency: 1
Reset counter 152
Mileage: 117664 km
Time Indication: 0
Date 2020.07.10
Time 18:45:25

Any help appreciated as its really annoying!