Brake servo restricted

[Deco]

On 12/18/2021 at 1:15 AM, Deco said:

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

Is there any video links or tutorials on how to replace brake servo sensor a4 2017. TIA

[FADEC]

54 minutes ago, Deco said:

Is there any video links or tutorials on how to replace brake servo sensor a4 2017. TIA

 

[Deco]

23 hours ago, FADEC said:

 

Thank you!!

[benfoz]

Same issue here, i changed the sensor (too late, after 20 cycles so the 'stop driving' error never cleared) i just kept driving, presuming that because the sensor was new the whole thing is a ridiculous digital issue rather than mechanical issue with the brakes. That was 6 months / 15,000 miles ago, and the brakes have been fine. I've got the MOT next week and concerned that because of the light on the dash it'll fail. Does anyone know who can attempt the ABS refurb/reset? Best try that before the £3k dealer battle. 

Thanks for you time! 

[DevQ7]

Hi Benfoz.

Same thing happened to me and it will fail the MOT. I sent mine to 2 different specialists who both said it can't be reprogrammed so i had to go to audi and have the ABS unit replaced. Ring around at the different audi garages near you as the prices i got ranged from 2.5k - 4.5k. I got quotes from local garages also but they're were the same price as the cheapest Audi garage at 2500 as its only a genuine audi part they could use so i just went with audi.

Hope this helps

Dev

[benfoz]

8 minutes ago, DevQ7 said:

Hi Benfoz.

Same thing happened to me and it will fail the MOT. I sent mine to 2 different specialists who both said it can't be reprogrammed so i had to go to audi and have the ABS unit replaced. Ring around at the different audi garages near you as the prices i got ranged from 2.5k - 4.5k. I got quotes from local garages also but they're were the same price as the cheapest Audi garage at 2500 as its only a genuine audi part they could use so i just went with audi.

Hope this helps

Dev

Thanks Dev! I'm going to try these people first, found in another thread:

https://www.ecutesting.com/common-faults/audi/audi-abs-brake-booster-fault/ 

Must be such a common issue for them to create a dedicated page and promo video for it. I don't suppose that was one of the ones you tried? Just need to get my local to get my unit out so that i know the part number for them to confirm. Fingers crossed. If not, thanks for the heads up about quotes from different audi dealers, i would have assumed they were all the same fixed price. Thanks!

[DevQ7]

Hi. Yes this is one of the places my garage sent mine to. Hopefully you have better luck with it than i did. Keep me posted. 

Out of interest where are you based?

[benfoz]

@DevQ7 Will do! I'm near Plymouth.

[Rob KEARNEY]

Hi all, firstly thanks to all for their contributions on this thread to help highlight and fix this very serious issue.  Some background information.  I am based in Ireland and in 2017 bought a new A5 coupe 190bhp 2.0 TDi from an Audi main dealer here - this car has always been serviced through this dealer.

With regard to this brake servo restricted issue I have been more fortunate than others and their experiences.  The warning message first appeared in September 2021 (though with no accompanying start / stop function warning).  However, this fault message disappeared after a few days and had been intermittent over the following weeks leading me to believe there was a loose connection somewhere.  In early December the warning appeared again along with the stop / start function warning.  Not realising the significance of continuing to drive with these warnings thankfully I only did limited mileage (this not by design) and yesterday I finally "googled" the issue.  It was only through this forum / thread did I realise the potential to cause damage to the ABS system with a possible repair bill of €4,000+.

So as of yesterday evening I stopped driving the A5 and this morning I rang my local Audi dealer to order the brake pressure sensor hoping they would have a unit in stock.  They did (cost = €107) and all I had to do was mention the part and the guy knew exactly the part number I required - so obviously a wide spread issue with Audi !  It took less than 5 minutes to change out the old sensor for the new and on starting the warnings were gone with standard brake foot pedal pressure restored.

My advice is similar to others on this thread - don't ignore the warning and you can easily replace the sensor yourself without resorting to Audi garage for high labour and diagnostic review costs.

Thanks again to all the contributors here ...........

[benfoz]

Quick update, after driving 15k with the ABS module bricked by this silly situation, I finally got it sent off and fixed by ECUtesting for <£300. No more lights on the dash! Do check if they can recondition yours before shelling out to audi for this criminal fault. 

[Steve Q]

On 1/20/2022 at 8:32 PM, benfoz said:

Quick update, after driving 15k with the ABS module bricked by this silly situation, I finally got it sent off and fixed by ECUtesting for <£300. No more lights on the dash! Do check if they can recondition yours before shelling out to audi for this criminal fault. 

Great bit of advice 👍

[Amffarkas]

Yet another guy who's fallen into the trap! My quote is closer to £3500 for the ABS Unit, Brake pressure sensor, and programming. 

Thankfully I found this thread and will send it off to ECU Testing.

I can replace the sensor myself no problem however the ABS Module looks a bit more tricky as some of the bolt look very inaccessible. Can anyone point me in the right direction? Can't seem to find any videos of removal/replacement.

[Afiac]

Hi all, new to this site but just thought I'd share my experience. We have our 2016 A4 about 7 months and the fault showed up about 2 weeks ago. Thanks to this thread for making us aware of dangers of driving the car. We drove it the bare minimum just a mile a day to the school and back. There is  2 week waiting list to be seen by the Audi garage an hour away so just brought it to my local independent garage. £20 for diagnostic on Friday gone by and £137 all in today ( £20 labour £25 diagnostic and £69 for part plus the vat ) I got away reasonably light compared to some unfortunate people here. 

[Steve Q]

On 1/26/2022 at 3:18 PM, Amffarkas said:

Yet another guy who's fallen into the trap! My quote is closer to £3500 for the ABS Unit, Brake pressure sensor, and programming. 

Thankfully I found this thread and will send it off to ECU Testing.

I can replace the sensor myself no problem however the ABS Module looks a bit more tricky as some of the bolt look very inaccessible. Can anyone point me in the right direction? Can't seem to find any videos of removal/replacement.

So glad we've saved you some money 🙂

[Steve Q]

On 1/26/2022 at 9:36 PM, Afiac said:

Hi all, new to this site but just thought I'd share my experience. We have our 2016 A4 about 7 months and the fault showed up about 2 weeks ago. Thanks to this thread for making us aware of dangers of driving the car. We drove it the bare minimum just a mile a day to the school and back. There is  2 week waiting list to be seen by the Audi garage an hour away so just brought it to my local independent garage. £20 for diagnostic on Friday gone by and £137 all in today ( £20 labour £25 diagnostic and £69 for part plus the vat ) I got away reasonably light compared to some unfortunate people here. 

Glad this thread helped you 🙂

[Duke Dukington]

Would just like to add my thanks too - fault seen on Sunday (30th Jan) popped to Audi on Monday morning and picked up the part which is now 85 quids and swapped it when I got home.

All looks good, just happy the fault didn't occur while I was in France last weekend!!

[Deco]

Not looking good changed brake servo sensor still have red warning light with beep. 😞

[Steve Q]

3 hours ago, Deco said:

Not looking good changed brake servo sensor still have red warning light with beep. 😞

Your next point of call in is a diagnostic check. 

[Nicholas fraser]

A bit off topic but doesn’t anyone know anything about this problem A4 Allaroad (B9) 

[Duke Dukington]

23 minutes ago, Nicholas fraser said:

A bit off topic but doesn’t anyone know anything about this problem A4 Allaroad (B9) 

 

Your car has a seperate adblu tank. It's used to help with emissions. The tank is nearly empty and needs to be filled. On my car, you'll find the filling point next to where you fill your car with Diesel (it's the blue coloured cap) Most cars take 12 litres, but some have a 24 litre tank.

You can buy Adblu from most petrol stations - some even have a Adblu pumps, but I've not come accross any

[Nicholas fraser]

16 minutes ago, Duke Dukington said:

 

Your car has a seperate adblu tank. It's used to help with emissions. The tank is nearly empty and needs to be filled. On my car, you'll find the filling point next to where you fill your car with Diesel (it's the blue coloured cap) Most cars take 12 litres, but some have a 24 litre tank.

You can buy Adblu from most petrol stations - some even have a Adblu pumps, but I've not come accross any

The AdBlue tank is full it only appears in the morning on a first drive then goes away for the rest of the day. Think it’s a dodgy sensor  

[Duke Dukington]

15 minutes ago, Nicholas fraser said:

The AdBlue tank is full it only appears in the morning on a first drive then goes away for the rest of the day. Think it’s a dodgy sensor  

my mistake - shoulda read the message properly!

[Deco]

So I have this dreaded c123efo code in regards to my ecu audi a4 2017, I went up to the dealer I bought the car off and I was told the car needs to be remapped and to bring it to them in two weeks. Question is remapping a solution to this issue. I have this car less than a year when this problem occured and when they were doing a service the mechanic accidently spilled coolant on the engine when he was replacing my filter, which happened to spill all around the plastic cover that hides the servo sensor and other components like brake fluid etc. Should I have to pay if it is a re mapping issue? If I have to have the ecu rebuilt how much will that cost all in. TIA!!

[Steve Q]

Hmm if it's asking for the part then I'd be changing the sensor. A remap should only be a deleting fault codes. 

[Deco]

7 minutes ago, Steve Q said:

Hmm if it's asking for the part then I'd be changing the sensor. A remap should only be a deleting fault codes. 

I have already changed the servo sensor, but the c123efo code is still there. Does the car recognise the original part if it is rebuilt?