Starting issues Code 01672

Hey guys unsure if I am in the right section.

Having some issues with my 2006 S6 5.2L V10 Audi.

Getting the following codes with Snap-on Scanner

01672 - Main Relay, Load Circuit Open Circut
05715 Read DTC Memory of break ECU

Car wont start at all and it throws a whole heap of codes but those are the main ones that I keep seeing. Has anyone experienced this before or could put me in the right place to start. Sometimes I can lock the car up for 5-10 minutes come back out and it will start fine. This is probably the 5th time its done it now within 2 months.

Only issues I can put it down to be is a Faulty Relay which is causing the car to lose complete communication or possible battery fault how ever Ive checked the battery level each time and its between 90-100%

Cheers,

​​​​​​​Ben