Brake servo restricted

[Stagn8]

Probably will do the same as I don’t know which supplier AUDI actually use.

[Neat]

Hi all

have a q5 ‘19 18k on the clock. Brake servo restricted and start stop error came on last night whilst driving. Anyone have this happen to a newer car? As see it seems to be ‘66 plates. Reluctant to drive having read this thread. Will be ringing Audi Tunbridge Wells today. As a manufacturer fault this should be covered under warranty? 
 

thanks

[mole122]

1 hour ago, Neat said:

Hi all

have a q5 ‘19 18k on the clock. Brake servo restricted and start stop error came on last night whilst driving. Anyone have this happen to a newer car? As see it seems to be ‘66 plates. Reluctant to drive having read this thread. Will be ringing Audi Tunbridge Wells today. As a manufacturer fault this should be covered under warranty? 
 

thanks

If it’s a 2019 or should be within warranty anyway shouldnt it? Just ring your Audi assist - they came out within the hour to me! 
if you’re out of warranty and it’s only just come on, then you will probably get away with the £80 sensor change. 

[123456789987654321]

Does anyone have the part code for sensor needed? Our car is the following;

Audi A5 DIESEL SPORTBACK - 2.0 TDI Quattro S Line 5dr S Tronic (2017 Plate)

Cheers

[P3N]

It’s a really helpful forum Joe.  If you make the effort to scroll through this topic you will find the part number mentioned several times.

[djrichs]

If this help anyone, here's my experience.

I've just had the brake servo restricted message on my 2016 A4. I then drove it 20 miles to work the next day without the message. I started looking on here and from what I read I rang an independent AUDI specialist. They told me not to drive the car and have it recovered as the ABS could get corrupted and seize, which would result in a £3500 bill for new ABS unit. Car was towed under my breakdown cover no questions asked.  £234 later and the car seems fine today. Charged 2 hours labour to diagnose and fit the sensor, £12 ODIS charge, which seems excessive. But, its not £3500.

When I picked it up the guy said the the error count had reached 2, and when it reaches 7 then the ABS is corrupted. Id only driven it 30 miles in total and had 1 on screen dash message. 

AUDI definitely should be ashamed!

[P3N]

Hi Dave

Well you should pat yourself on the back and also immediately run your luck and buy a lottery ticket 😎 cos you’ve saved yourself over £3k.  Happy Days.
This forum is keeping a lot of people safe let alone sane. It shouldn’t be necessary to have to rely on luck when you drive a quality car but it seems the powers that be are shameless.  Pen

 

 

 

[kiwiA5]

My wife's 2017 A5 had the same issue today. Hope it doesn't compromise the abs but I simply disconnected and then reconnected the wiring connector to the sensor and this cleared the errors. Test drove and all seems normal.

Edited November 22, 2021 by kiwiA5

[Magnet]

Hello Sean,

Thanks for being in touch.

Can I be excused for thinking you are taking an unnecessary risk here by not simply replacing the relatively cheap offending component, before this reoccurs and expensively bites you in the bum? 
Kind regards,

Gareth. 

[Steve Q]

On 11/22/2021 at 5:23 AM, kiwiA5 said:

My wife's 2017 A5 had the same issue today. Hope it doesn't compromise the abs but I simply disconnected and then reconnected the wiring connector to the sensor and this cleared the errors. Test drove and all seems normal.

If it were me I'd just change the sensor. Cheapness could cost someone dearly. A d not just financially! 

[A4s-line]

Hi, if anyone needs a replacement sensor, I have one that I would be happy to sell. We ordered two whilst in France in the summer (one via internet and one posted from a main dealer) The dealer one didn’t arrive before we headed home but when we went out again in November, it was sat waiting in the postbox. I have just listed it on eBay for £50 if anyone is interested. Just search the part no. 5Q0906207B. Many thanks. 

[StevieB-uk]

Hi, I’ve read through this entire thread (absolutely shocked at this issue) and wondered if the symptoms my 2016 A6 C7 (38k miles) has just started displaying is the brake servo sensor issue or could this be the Abs speed sensor on one of the wheels or both?

I started it got the errors, the car was driven 2 miles when I got to destination it wouldn’t”t stop. The start stop button just wouldn’t stop the car. After 5 mins and pressing it continually it did. Picked up my son and went to drive home. Same set of errors except this time I had no power steering. Drove home 2 miles home and stopped it. Restarted after 10 mins and same set of errors and power steering working again.

I’ll be ordering a brake servo sensor as soon as Audi parts open this morning but wondered whether I may have a more serious issue?

Any advice greatly appreciated.

[Steve Q]

6 hours ago, StevieB-uk said:

Hi, I’ve read through this entire thread (absolutely shocked at this issue) and wondered if the symptoms my 2016 A6 C7 (38k miles) has just started displaying is the brake servo sensor issue or could this be the Abs speed sensor on one of the wheels or both?

I started it got the errors, the car was driven 2 miles when I got to destination it wouldn’t”t stop. The start stop button just wouldn’t stop the car. After 5 mins and pressing it continually it did. Picked up my son and went to drive home. Same set of errors except this time I had no power steering. Drove home 2 miles home and stopped it. Restarted after 10 mins and same set of errors and power steering working again.

I’ll be ordering a brake servo sensor as soon as Audi parts open this morning but wondered whether I may have a more serious issue?

Any advice greatly appreciated.

BFB2A0D5-9765-4FAB-85E0-E351FB3566E9.MOV

I definitely think you'll need a diagnostic check to see whst fault codes flag up.  

[StevieB-uk]

14 hours ago, StevieB-uk said:

Hi, I’ve read through this entire thread (absolutely shocked at this issue) and wondered if the symptoms my 2016 A6 C7 (38k miles) has just started displaying is the brake servo sensor issue or could this be the Abs speed sensor on one of the wheels or both?

I started it got the errors, the car was driven 2 miles when I got to destination it wouldn’t”t stop. The start stop button just wouldn’t stop the car. After 5 mins and pressing it continually it did. Picked up my son and went to drive home. Same set of errors except this time I had no power steering. Drove home 2 miles home and stopped it. Restarted after 10 mins and same set of errors and power steering working again.

I’ll be ordering a brake servo sensor as soon as Audi parts open this morning but wondered whether I may have a more serious issue?

Any advice greatly appreciated.

just thought I would update this so anyone else who gets this issue can see how it was fixed.

replacing the brake servo pressure sensor didn’t fix my issue, however replacing one abs speed sensor on the front wheel did.

nuts to think that a failed speed sensor could cause all those errors. Even driving to the garage it gave me a clutch malfunction, stop safely error.

anyway, it’s fixed now….. until the next issue with this money pit 😳

Edited December 9, 2021 by StevieB-uk

[Magnet]

Hello Stevie,

As I understand it, the ABS sensor set up fundamentally gauges the wheel speed, and if this is correct, you can understand why you were getting so many false indications. 
Dare I say, your symptoms would have been a good reason to have plugged the car in to diagnostics which should have identified which wheel was at actually at fault. 
Anyway, all fixed now. 
Many thanks for letting us know.

Kind regards,

Gareth. 

[Steve Q]

On 6/21/2020 at 9:21 AM, neeko99 said:

Hi, everyone... I've had the same problem on our 2017 Q7... parked up for most of lock down and drove it for the first time in a while yesterday and the brake servo and start/stop error appeared... Seems to be a theme here across most models... 

Definitely is, the new sensor should fix it 👍

[Robt1]

Hi all,

Thanks for contributing to this post. My 68 plate A6 had this error pop up on Friday, I called Audi Roadside Assistance today and the technician fitted the replacement sensor within an hour. Things could have been a lot worse with the ABS wear so thanks all for posting about your experiences and highlighting the issue.  
 

The fact the responder was carrying this part on his vehicle says it all I think. 
 

Best,

Rob

[Steve Q]

3 minutes ago, Robt1 said:

Hi all,

Thanks for contributing to this post. My 68 plate A6 had this error pop up on Friday, I called Audi Roadside Assistance today and the technician fitted the replacement sensor within an hour. Things could have been a lot worse with the ABS wear so thanks all for posting about your experiences and highlighting the issue.  
 

The fact the responder was carrying this part on his vehicle says it all I think. 
 

Best,

Rob

Couldn't agree more. Just shows Audi know it's a common fault but do t want to admit it 

[chrisprice9021]

I was greeted by this message on my drive into work this morning, Googled it and thanks to this forum (hopefully) I have saved the ABS system.  Just need to coast it home tonight and work out how to get to Sheffield Audi to pick the replacement part...

[P3N]

Good luck Chris 🙏.   Keep us informed.

[Deco]

Had brake servo restricted warning which said you can continue driving, now its turned red saying braking system fault, has any had any issues of this nsture  and would replacing the servo sensor sort it? TIA

[DevQ7]

I had this same thing.  Sensor didn't change anything. Sent off the ABS control unit to see if it could be saved and it couldn't. Needed a new ABS control unit. Cost just under £3k. 

[chrisprice9021]

On 12/15/2021 at 4:32 PM, P3N said:

Good luck Chris 🙏.   Keep us informed.

Ta very much.

New sensor installed (v straight forward thanks to the instructions found here) and fault message is now gone.  Fingers crossed that this has nipped the issue in the bud.  

I purchased the part from Audi and on collection asked the parts guy if he sold many of them, to which he said yes: lots.  Criminal really…

[Steve Q]

1 hour ago, chrisprice9021 said:

Ta very much.

New sensor installed (v straight forward thanks to the instructions found here) and fault message is now gone.  Fingers crossed that this has nipped the issue in the bud.  

I purchased the part from Audi and on collection asked the parts guy if he sold many of them, to which he said yes: lots.  Criminal really…

Glad you got sorted ☺️

[kiwiA5]

On 11/22/2021 at 9:18 PM, Magnet said:

Hello Sean,

Thanks for being in touch.

Can I be excused for thinking you are taking an unnecessary risk here by not simply replacing the relatively cheap offending component, before this reoccurs and expensively bites you in the bum? 
Kind regards,

Gareth. 

 

On 11/24/2021 at 10:23 PM, Steve Q said:

If it were me I'd just change the sensor. Cheapness could cost someone dearly. A d not just financially! 

From information on various online posts and considering the fault message stated "you can continue driving" I assumed that there would be no risk of a serious brake failure and that if the part were indeed faulty then the message would soon reappear. As it turned out that is exactly what happened the following day. On having it diagnosed by the local Audi service agent they confirmed that the brake pressure sensor should be replaced at a quoted cost of $847.95!!! (GBP425). Having previous experience of overpricing for european car parts (major NZ parts supplier quoted $250 for a drive belt for a VW V5 golf which I ended up importing from a UK supplier ,same brand and part number total cost including freight $35!) I searched for the part number and found it widely available from various sources such as eBay, amazon and ali express. Prices varied but images all showed identical markings to the original part. A little research on brake booster pressure sensors in general revealed that these parts are normally expected to last the life of the vehicle. The fact that this particular VW sensor is so widely available from a variety of sources  strongly suggests that it is indeed a part that is prone to fail well before it's life expectancy. I purchased a replacement sensor for the A5 from ali express. Time to fit - under 2 minutes. Total cost of part including freight- $15 . I have since seen the same part online for as little as US$5.99.  Have Audi been using a very cheaply produced and inherently unreliable part that could lead to costly repairs to the ABS system? If so there should be a recall on all cars fitted with this part and a reliable replacement should be fitted free of charge. Regarding any warranty period- here in New Zealand we have the consumer guarantees act which basically states that anything you buy should be expected to last a reasonable time regardless of the manufacturers warranty period . For example if your appliance with a 1 year warranty fails after 18 months and the normal life expectancy of that type of appliance is 2-3 years then it must be repaired or replaced free of charge. I'm pretty sure the same applies to car parts.