Brake servo restricted

[kh904]

Sorry to hear on your troubles Claudster!

It's disgusting and an outright lie that Audi claim that they are unaware of the issue.

I believe a number of people on this forum have informed Audi of the issue.

Maybe someone can consult a class action lawyer/motoring organsiation to push our cases?

All Audi need to do is send out a recall notice and update the onboard computer to change the message so when the sensor fails, it should notify the driver to stop driving, park up and contact the dealer (not that it's ok to continue driving as it currently does).

[Teri]

Hey I have the same issue I just got my ecu fixed and now this sensor is on dash and I believe it needs the new sensor, is it safe to drive the car until I get it into mechanic to get it fixed? 

[kh904]

46 minutes ago, Teri said:

Hey I have the same issue I just got my ecu fixed and now this sensor is on dash and I believe it needs the new sensor, is it safe to drive the car until I get it into mechanic to get it fixed? 

Hi,

It's well worth reading the whole thread (it will answer all your questions and gives the sensor part code and fitting instructions).

Essentially I wouldn't bother driving it if possible until the sensor is changed - you are at risk of a heavy expensive bill to replace your ABS module!

The sensor can be picked up from eBay for around £20 (a chinese copy) or £90 (OEM from Audi) and swapping the sensor literally takes 2 minutes (it's so simple).

[Teri]

Thanks so much that's what I thought alright I just wanted a 2nd opinion, I am going to buy the part and put it in as soon as possible 

[Magnet]

Hello Teresa,

’As soon as possible’ maybe too late - unless you are not using it. 
Kind regards,

Gareth. 

[Teri]

I'm not driving it and getting it replaced today 

[Magnet]

Great - well that’s different from ‘as soon as possible’.

[P3N]

Well done moving swiftly Teresa. I do hope that all sorts out with the new sensor.  I was unlucky in that I believed the on board advice which said that I could continue driving and ended up with the full expenditure £3k +. I didn’t find this great forum in time..

Audi are quite shameless that they haven’t issued a recall. 

[Rick2022]

Had the same message about brakes servo and start and stop… called Audi roadside service and they found the fault… sent the information to Audi… drove to Audi next day and they changed the sensor for free, under extended warranty… car looks and feels fine to drive… had problems with ad blue unit in the first 3 months with the car (bought used from Audi) and they replaced it also without complain… until now, happy with customer service…

[Kisha]

I too had my car (2018 A4 B9) with less than 20000Km parked for few days, got the error, took it to the company says will have to change the sensor. But that’s kind of daft, for a German built vehicle, “sensor has to be replaced”. They should be able to reset it, I would have thought.

[kh904]

2 hours ago, Kisha said:

I too had my car (2018 A4 B9) with less than 20000Km parked for few days, got the error, took it to the company says will have to change the sensor. But that’s kind of daft, for a German built vehicle, “sensor has to be replaced”. They should be able to reset it, I would have thought.

Unfortunately you can't just reset the pressure sensor.

I think there is some sort of physical/mechanical operation within the sensor that operates with the brake pressure, but I could be wrong.

It is daft that a sensor fails so quick for a 'premium' brand.

[Kisha]

Agents said have to replace the part, and can’t reset from computer as it shows as a permanent error, before a certain “number” of brakes applied? Before it affects the ABS, which would be a far more costly replacement, Any idea?

[Magnet]

Hello Kishan,

Am I right in thinking you are still debating the need to change the sensor? If so, you would benefit from taking some time to read through the numerous posts, and then simply getting it renewed without further delay. 
Well that’s my ‘idea’.

Kind regards,

Gareth. 

 

[kh904]

7 hours ago, Kisha said:

Agents said have to replace the part, and can’t reset from computer as it shows as a permanent error, before a certain “number” of brakes applied? Before it affects the ABS, which would be a far more costly replacement, Any idea?

As 'Magnet' posted above, renew the sensor without delay and avoid driving the car if possible or you run the risk of 'bricking' the ABS unit.

It's a case of spending £20 for a aftermarket sensor (or £90 for a OEM Audi sensor), vs £2-3k for a new abs pump....

[cbrmick777]

Thanks to everyone who has added info to this topic.

I have a 2020 A4 40 TFSI Avant with 11,500 miles and got this error at the weekend. Thanks to the info here, I didn't drive any further. Called out Audi assist breakdown and they fixed it at home. Strangely they had the part in the van!

He also mentioned that it can lead to the ABS pump failure, so best to fix this as soon as you can.

[Steve Q]

On 12/27/2022 at 6:01 PM, cbrmick777 said:

Thanks to everyone who has added info to this topic.

I have a 2020 A4 40 TFSI Avant with 11,500 miles and got this error at the weekend. Thanks to the info here, I didn't drive any further. Called out Audi assist breakdown and they fixed it at home. Strangely they had the part in the van!

He also mentioned that it can lead to the ABS pump failure, so best to fix this as soon as you can.

Glad this thread helped you. 🙂

[Neilro]

On 12/27/2022 at 6:01 PM, cbrmick777 said:

Thanks to everyone who has added info to this topic.

I have a 2020 A4 40 TFSI Avant with 11,500 miles and got this error at the weekend. Thanks to the info here, I didn't drive any further. Called out Audi assist breakdown and they fixed it at home. Strangely they had the part in the van!

He also mentioned that it can lead to the ABS pump failure, so best to fix this as soon as you can.

To correct slightly, The ABS pump has an ECU in it. This has a fault counter which counts up to a pre determined number. When this number is reached it gives a do not drive message to the car dashboard. Audi cannot reset this fault. Audi's remedy is to replace the pump unit at a cost of £3300, or to do it on warranty.

A company called ECUTESTING.COM can reprogram the ECU module for £289 and it works. The fault I originally had was the vac sensor went faulty and I didn't get it fixed in time.

The pump is not faulty. The servo is not faulty. It is merely an ECU counter chip that cannot be reset by AUDI. Replace the vac sensor and then have the ECU reprogrammed.

This reprogramming works and is correct. Please check it out before being stung for what should be an Audi recall!

 

[kh904]

Great to hear there is a relatively cheap solution of the ABS 'bricks'!

It would be great of the mods can put a 'sticky' on the ecutesting.com as I feel it would be a great help to many people.

[Steve Q]

2 hours ago, kh904 said:

Great to hear there is a relatively cheap solution of the ABS 'bricks'!

It would be great of the mods can put a 'sticky' on the ecutesting.com as I feel it would be a great help to many people.

Glad this thread helped 🙂

[Magnet]

Thanks Harminder - will mention to administrators.
What this and other numerous-page threads needs is to ‘reverse’ it from its current format, and have the most recent posts first, to save wandering through 22 pages to get to the most recent.

I will re-raise this again.

Kind regards,

Gareth. 

[jdragon]

17 hours ago, Neilro said:

To correct slightly, The ABS pump has an ECU in it. This has a fault counter which counts up to a pre determined number. When this number is reached it gives a do not drive message to the car dashboard. Audi cannot reset this fault. Audi's remedy is to replace the pump unit at a cost of £3300, or to do it on warranty.

A company called ECUTESTING.COM can reprogram the ECU module for £289 and it works. The fault I originally had was the vac sensor went faulty and I didn't get it fixed in time.

The pump is not faulty. The servo is not faulty. It is merely an ECU counter chip that cannot be reset by AUDI. Replace the vac sensor and then have the ECU reprogrammed.

This reprogramming works and is correct. Please check it out before being stung for what should be an Audi recall!

 

This is very informative. 

Just to check my understanding; are you saying even when the sensor has been replaced and the error disappears, it's also necessary to have the ECU counter reset?

[kh904]

2 hours ago, jdragon said:

This is very informative. 

Just to check my understanding; are you saying even when the sensor has been replaced and the error disappears, it's also necessary to have the ECU counter reset?

It's not necessary to have the ABS ECU reset, UNLESS it reached the the fault counter limit and bricked the ABS module.

 

[Neilro]

Yes, you don't need to have the ECU rest unless like me you got the do not drive message. Then the only option according to Audi is to renew the ABS at a cost of £3300, or do what I did and send just the ECU (which unbolts from the ABS pump) to ECU testing. Reprogram is £289 inc postage.

[jdragon]

Such valuable information here guys - thanks for the clarification 🙂

[Steve Q]

11 hours ago, jdragon said:

Such valuable information here guys - thanks for the clarification 🙂

Glad it's been useful 🙂