Just wanted to post my issue and more importantly the solution. Started car to commute to work only to find the dash was lit up like a Christmas tree! Drove to work fine, despite the warning lights (none were dangerous), but noted front and rear parking sensor, cruise control, stop/start no longer worked.  On finishing work started car to find all warnings had cleared and so drove home perplexed but relieved that car was fully functional again, however on arrival (30 mins) I decided to stop and then try restarting which resulted in all the warnings returning 🤦🏻‍♂️ and remained present for weeks. The codes were; Engine fuel limitation U111300, Steering assistance U111300, Parking brake U111300, Electronic parking brake J540 (00473), Brake control module 01316, Right Rear ABS sensor 00287. However nothing regards parking sensors or Stop/start.

Tried a few things over the following weeks however finally discovered all caused by the defective right rear ABS sensor, which had imploded in the hub due to corrosion in the ABS pocket, resulting in having to drill the old sensor out! For info Audi sensor £150 but went for a £10 part from Spares Hut, obviously OEM is best but some times I draw the line at these crazy inflated prices.

Edited March 1, 20251 yr by Tugg
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In a lot of cases multiple warning lights can be caused by a failing battery 

Yes Steve Q, I saw this when I was trawling through previous forum posts for solutions, and this was the first thing I changed based on the loss of stop/start and multiple lights. But the new Halfords AGM 019 battery (92AH) made no difference at all. 

Nice one. Has the abs sensor resolved all the issues? 

If not, is your battery in the boot? 

If I do I remember a member with an A6 c7 that was having a similar problem and it transpired the main electrical cable running from the battery in the boot to the dash had become loose.  In their case it was loose under the rear passenger seat so whenever someone sat on the seat it caused the Christmas tree dash. 

Yes Steve, as I say in original post the solution was replacing the ABS sensor.