Simon Ryder

3 minutes ago, zap263 said:

Thanks mate.. legend!!

My local Audi said £170 just to diagnose the fault!  And the car had only been out of warranty a month! 

Part is £70+vat from TPS.. hope this fixes it.

No worries, good luck. 
I was advised by my mechanic mate to pump the brake pedal when engine is off first? Two/three pumps and it stiffens up. Something to do with balancing the pressure?  
It does feel like a win when you start the car and it all works, for a fraction of the price. 

6 hours ago, zap263 said:

Hi Simon.. can you take a pic of what it looks like and where exactly you found it? 

 

Will help myself and a lot of folks here loads!

 

Cheers.

Hope this helps. 
I’ve circled in red the area of the sensor. It’s under a plastic flap. You have to pull the rubber edge off to lift up. 
The sensor pulls vertically off. You then slide a plastic holding clamp off the other end. Just reverse the process to put the new one back in. It’s really simple and annoying that everyone seems to want to charge a couple of hundred pounds for this??!?

6 hours ago, martina o said:

can u still drive it ?

Yep, it took literally a minute to unplug the old one and replace with the new one. All the warnings have gone off and the brake feels normal again. 
 

Hi,

I had exactly the same problem as you all have reported. 
I ordered a Brake servo pressure sensor from the Audi Parts Department at my local Audi dealership. 
It was really really easy to replace like for like. I have no experience with car maintenance. I’ve got the A4 and it was to the top left of the engine compartment, under a plastic covering that lifted up. I’d recommend having a go. It cost me £75 for the part.