Brake servo restricted

[Stagn8]

I have bought exactly the same one and it is in the glove box ‘just in case’ as so far not had the problem 🤞🏻. I think the price is about right as if it is a pressure sensor all that’s likely to be in there is a sprung loaded bit of material which reacts to the vacuum generated in the servo and relays an ‘on’ message to an ecu to confirm the servo is operating. If the ecu doesn’t get the signal then it compensates by operating the abs unit, which we all know know can’t take fairly continuous operation.

No idea how VAG justify their prices but the one I received has ‘made in Germany’ on it, so hopefully not been anywhere near China. Having said that, the Chinese are more than capable of producing very high quality parts if they want/need to and I am pretty sure all the German manufacturers have a fair smattering of Chinese parts made to their own exacting standards. ( Not sure what standards were being followed for these sensors though, pretty minimal ones I would hazard)
 

[audi999]

On 4/13/2022 at 7:39 PM, Deco said:

It takes 5 minutes to replace the brake servo sensor, at least another 5 to clear the fault. They charged my pal 660 to do the work on his car. I personally replaced mine by myself and I am certainly no mechanic.  They are rip offs!! 

 

£660 !!! That is tantamount to theft. Had mine done at my local indie. Genuine Audi part fitted in five minutes. Five minutes to clear the code. Total cost - less than £100

[Vanderlust]

Small update - I asked about buying a £10 sensor on eBay before and ended up buying it to see if it worked. 
 

Fitted it myself and it cleared the error message right away. Been driving for couple weeks now and so far so good!

 

Total cost about £10 delivered. Saw a few of those sensors (original type) on eBay now. Seems that they do work, and not sure what the updated version benefit is. Maybe more reliable. If this one goes I’ll fit a newer B one.

[Steve Q]

4 hours ago, Vanderlust said:

Small update - I asked about buying a £10 sensor on eBay before and ended up buying it to see if it worked. 
 

Fitted it myself and it cleared the error message right away. Been driving for couple weeks now and so far so good!

 

Total cost about £10 delivered. Saw a few of those sensors (original type) on eBay now. Seems that they do work, and not sure what the updated version benefit is. Maybe more reliable. If this one goes I’ll fit a newer B one.

Glad you got sorted. It's nice to know the aftermarket ones work just as well. Thanks for letting us know 😊

[888MB]

All, 

 

just had this error appear on my dash S4 b9 2017.  
 

driven daily so hasnt been parked idle for long periods of time. 
 

booking in with audi as i also have no AC working - lets see what they say. 
 

hopefully i can argue my case, a 2017 and two common faults (reading online)

☹️☹️☹️☹️

[Steve Q]

1 hour ago, 888MB said:

All, 

 

just had this error appear on my dash S4 b9 2017.  
 

driven daily so hasnt been parked idle for long periods of time. 
 

booking in with audi as i also have no AC working - lets see what they say. 
 

hopefully i can argue my case, a 2017 and two common faults (reading online)

☹️☹️☹️☹️

The pressure switch you can change yourself. Not worth the risk of doing further damage. 

[Firkindolloper]

My brake servo problem still exists yet no message but I can start it by pressing harder on the brake pedal - yes, that's what Audi said - so I have just bought a sensor in case I get the dreaded message ......

Being such a common problem, you would think that a hi-tech car manufacturer with "quality" products would have eradicated this issue by now.

Edited May 16, 2022 by Firkindolloper

[Jaime A5 Quattro]

I have this problem only if my car is parked up for over 10 days. Luckily a 5+ mile drive clears the fault at the moment. 

[lozzd]

32 minutes ago, Jaime A5 Quattro said:

I have this problem only if my car is parked up for over 10 days. Luckily a 5+ mile drive clears the fault at the moment. 

And every time you touch the brakes even lightly during that time, it's draining your finite power from your ABS module. Replace it now before you have a £3k+ bill

[Steve Q]

8 hours ago, Firkindolloper said:

My brake servo problem still exists yet no message but I can start it by pressing harder on the brake pedal - yes, that's what Audi said - so I have just bought a sensor in case I get the dreaded message ......

Being such a common problem, you would think that a hi-tech car manufacturer with "quality" products would have eradicated this issue by now.

I'd change the sensor anyway if you haven't already as the car could just be masking the problem in your case. 

45 minutes ago, Jaime A5 Quattro said:

I have this problem only if my car is parked up for over 10 days. Luckily a 5+ mile drive clears the fault at the moment. 

I'd advise changing the sensor anyway. As it could lead to a big bill otherwise. Bet safe than sorry in my opinion. 

 

[Steve Q]

12 minutes ago, lozzd said:

And every time you touch the brakes even lightly during that time, it's draining your finite power from your ABS module. Replace it now before you have a £3k+ bill

Couldn't agree more with you 👍

[Jaime A5 Quattro]

14 minutes ago, lozzd said:

And every time you touch the brakes even lightly during that time, it's draining your finite power from your ABS module. Replace it now before you have a £3k+ bill

Wow, it’s something I will definitely have to look at doing asap if that’s the case. 

[Jaime A5 Quattro]

6 minutes ago, Steve Q said:

I'd change the sensor anyway if you haven't already as the car could just be masking the problem in your case. 

I'd advise changing the sensor anyway. As it could lead to a big bill otherwise. Bet safe than sorry in my opinion. 

 

Definitely on my to do list, luckily my car is used daily it’s only the odd occasion it’s left more then 10 days but definitely worth doing. 

[Steve Q]

Just now, Jaime A5 Quattro said:

Definitely on my to do list, luckily my car is used daily it’s only the odd occasion it’s left more then 10 days but definitely worth doing. 

For how cheap the part is I wouldn't put it off in my opinion. Especially when the braking system is arguably the most important system in the car. 

[kh904]

3 hours ago, Jaime A5 Quattro said:

Wow, it’s something I will definitely have to look at doing asap if that’s the case. 

Apparently the ABS unit bricks once it reaches 20 'cycles' (I'm not sure what counts as 1 cycle), so my advice is do not drive it until the sensor is replaced.

It simply isn't worth taking the risk.

Even of you by a new aftermarket sensor from eBay for £10-20, it's worth just replacing it

[kh904]

3 hours ago, Jaime A5 Quattro said:

Definitely on my to do list, luckily my car is used daily it’s only the odd occasion it’s left more then 10 days but definitely worth doing. 

The fact that you are driving it daily is increasing the risk of bricking the abs system!!! There's more risk that the abs hits another 'cycle' trigger, which it's not possible to do if you don't drive the car.

If possible, use another car if you have access, public transport or hire a car while you wait for the part to be delivered.

[Jaime A5 Quattro]

On 5/16/2022 at 7:42 PM, Steve Q said:

For how cheap the part is I wouldn't put it off in my opinion. Especially when the braking system is arguably the most important system in the car. 

Have you a part number before I order and any fitting information. 
 

Thanks in advance 

Jaime 

[kh904]

The part number on my invoice (from the Audi dealership) is:

A5Q0906207B

 

 

[FADEC]

There are a few videos and fitting guides in this thread. 

4 hours ago, Jaime A5 Quattro said:

Have you a part number before I order and any fitting information. 
 

Thanks in advance 

Jaime 

 

[Rich867]

On 5/9/2022 at 12:28 PM, Bri H said:

Not sure if this is allowed but here is the part I got off ebay "parts for German cars"  https://www.ebay.co.uk/itm/AUDI-A4-B9-50-TDI-Brake-Booster-Pressure-Sensor-5Q0906207-5Q0906207A/234133225811 looked no different to the part I removed. Yes I understand it could be a very good Chinese copy, but the add does they do not use these. UK based and 2yrs warranty, part arrived in 2 days. Also found the part on Amazon for £12.99.

I bought one of these off eBay, arrived in two days and just fitted it this afternoon.  Brake pedal was stiff when I went to start the car but once car started presumably the servo kicked in and worked normally.  Took it for a spin to check the brakes were working and seemed fine.  Will be going on a longer journey so will report back if I encounter any problems.

[Rich867]

On 5/19/2022 at 10:13 AM, kh904 said:

The part number on my invoice (from the Audi dealership) is:

A5Q0906207B

 

 

What is the difference with the B version, I got mine off eBay and I used the compatibility checker on the listing and it just had the numbers.

[kh904]

Just now, Rich867 said:

What is the difference with the B version, I got mine off eBay and I used the compatibility checker on the listing and it just had the numbers.

I have no idea.

 

The 'B' is a newer version, but I have no idea what actual difference there is. I don't know if it's better quality internals, or something else.

If someone knows, i'd be interested to know too!

[Jaime A5 Quattro]

On 5/19/2022 at 10:13 AM, kh904 said:

The part number on my invoice (from the Audi dealership) is:

A5Q0906207B

 

 

Ordered yesterday thanks for the part number 👍🏻

[Rich867]

17 hours ago, kh904 said:

I have no idea.

 

The 'B' is a newer version, but I have no idea what actual difference there is. I don't know if it's better quality internals, or something else.

If someone knows, i'd be interested to know too!

I had a look through earlier bits of this thread and someone mentioned the B might be the improved version.  Makes sense as this seemed to impact cars from a certain period, 16-18 was mentioned.  If this is the case the B would make it easier to diagnose issues but does beg the question why they didn’t do this as part of a recall or service programme.  The other thought was whether the eBay versions are more or less robust if they are based on the original, has anyone gone through more than one replacement?  If so how long did the first replacement last?

[kh904]

2 minutes ago, Rich867 said:

I had a look through earlier bits of this thread and someone mentioned the B might be the improved version.  Makes sense as this seemed to impact cars from a certain period, 16-18 was mentioned.  If this is the case the B would make it easier to diagnose issues but does beg the question why they didn’t do this as part of a recall or service programme.  The other thought was whether the eBay versions are more or less robust if they are based on the original, has anyone gone through more than one replacement?  If so how long did the first replacement last?

It should be criminal that Audi haven't sent out some sort of notification to owners who maybe potentially affected!

They also need to update the message on the dash, as it gives the incorrect impression that you are ok to continue to drive without any consequences!

 

I'm also interested to know if people have gone though more than one replacement part (was it a genuine Audi part or a copy from eBay?). Still unsure how the revised 'B' version is any different!