Audi A5 Fault Code Fun

[A Winner Is You]

Made the fatal mistake of telling someone at work how the car has been completely reliable until now. Got in to start it this morning and get hit with an array of faults - ABS, TCS, headlight adjusters, stop-start and parking brake (which still worked) all inoperative, as was the parking sensors. Call out the RAC who read the code as a rear ABS sensor fault, which would explain the first two but have no idea how it relates the the rest. Out of interest I tried it a few hours later and everything but the stop-start worked.

Any ideas why? If it is the sensor I don't understand why that would cause unrelated systems to stop working, and seems odd it would work fine on the drive home and give up once you start it in the morning. Or could it be the battery on the way out and dropping voltage? Car is a 2012 A5 TDI cvt. Many thanks.

[catso]

I had an A3 that had an ongoing battery drain issue. If ever the battery got low (which it did if left unused) then after starting the car it would throw up most of the available errors in turn, including gradually reducing the available gears (DSG gearbox) until the car ended up stopping in neutral.

Switching off and restarting would cure it as would having a fully charged battery.

Audi dealer couldn't/wouldn't explain or understand what was happening so I never actually got confirmation of the how/why.

[sleepersix]

I had exactly the same issue in my 2010 S5 just before Christmas: ABS fault, TCS, headlight range control, parking brake. Changed the ABS sensor in one of the front wheel arches which sorted it all. Changed the battery at the same time as well, as low charge can also cause fault lights as mentioned above. Hope you sort it ok