48v system failure

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ducnick

Original Poster:

1,793 posts

244 months

Wednesday 10th April
quotequote all
I couldn’t find much in the forum so I thought I would mention it here as a warning.

All Audis that use the 48v battery and starter generator since approx 2016 are potentially prone to a very expensive failure. This included my 60k mile, 2019 q7 50tdi, but it runs right up to q7/8’s being built today.
The generator circuit of the starter generator fails and you get an Amber warning light telling you about an electrical system failure and stop start is unavailable. The car starts and drives normally. If you drive it (which the dealer will tell you is fine to do) the 48v battery will be flattened and the power steering will shut down.
The generator will cost you approx £2000 to replace at a dealer. If the battery is killed, that costs approx £1500 to replace. Obviously the parts are all out of stock and your dealer will take at least 2 weeks to get the parts and find an engineer qualified on the hybrid system to fix it.
These failures are big news in the USA where most Audis seem to use the same components and there is the normal class action lawsuit going on. For reference it doesn’t appear to be age or mileage related in the USA with reports of it occurring at all sorts on mileages and even on very new cars.

Anything with the 50 TDI, 45tdi, 55tfsi engines are affected.
Strangely the Porsche cayenne isn’t affected as they use a different system. The v8’s don’t appear to be affected either. Presumably the vw toureg is also subject to this failure.

If it happens to you, my advice is to not drive it more than 5 miles then get it on a 12v battery charger and leave it on there until Audi can trailer it away. If you put it on a 12v maintenance charge it will automatically keep the 48v battery charged and healthy.

The good news is that this is covered by your Audi warranty if you have one. Aftermarket warranties may not be so accommodating.

Edited by ducnick on Wednesday 10th April 07:58

FMOB

885 posts

13 months

Saturday 13th April
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Owning a 2021 S6 Avant, why am I not surprised.

I got the car pegged as a pile of crap that I regret buying.