brake servo restricted


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Is your car a B9? If so it should have a warranty and I'd be calling out Audi Assist...


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I have just had the above warning appear on my A5 MY17 2.0 TFSI, with advice that you can continue to drive the car. Luckily, I came across this lengthy thread on another A4 forum which I feel is worth linking, as the fix is simple and the consequences of continuing to drive could be expensive. It’s worth noting that the ABS module can be damaged if you continue to drive with the fault. The malfunction caused by the brake servo sensor seems to be quite common, mainly in the MY17.

I also mentioned in the thread to avoid some online parts companies that are actually based in Germany and seem take forever to dispatch orders.
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Cheers Dave. That’s good to know should the worst happen to other owners


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Just to re draw everyones attention to this as it is a potentially costly fault.

It seems from searching around various forums this is now a fairly common problem. It manifests itself as a "Brake servo restricted" warning together with a start/stop fault. Unhelpfully it suggests that you can continue to drive the car, however to do so would be extremely unwise.

I have just suffered this problem and was able to replace the brake pressure sensor myself (part no 5Q0906207B) for £79. Part sourced from local Audi dealer. The guy at the desk said they are now selling multiple sensors a week (and it isn't just the A4). It's a quick fix if you search for "brake servo restricted" online. However, if you continue to drive the car you could end up having to replace the entire ABS system for north of 3k. It has happened to people.

Be warned!


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I just bought a 2017 S5 so I thought I would check.


It looks like I have the latest version "B", which according to ETKA was only available from 01/03/21.
Maybe the previous owner had replaced it already or do they all just fail.