Abs sensor type problem

[Daniel9944]

Hi everybody have an A6 saloon from 2013 and have a very particular problem constantly. There are 4 error messages comes up literaly all the time: tpms system fault, parking brake, abs system fault, start/stop system fault. Now I took the car to 4 different mechanichs none of them knows what is the problem. One of the abs sensors come up as fault on diagnosticts but it’s been replaced twice problem is still there. They tried to clen the wires and the disc it made the problem go away for a month or so but it’s back since. What should I do where should I start looking?

thanks,

Dnaiel

[Magnet]

Welcome Daniel,

Multiple warning lights, and particularly with associated stop/start failure can be typical of a below par battery. 
How old is your battery? 
It would be worth having its efficiency check with a sophisticated testing facility. Don’t assume because it starts OK, that the battery is serviceable in all tested parameters. The likely-fitted Battery Condition Monitor will probably have a different view! 
Need a new battery? Invest wisely in a min. of 4 year warranty batteries. I’ve used Varta/Bosch to good avail, and I think Exide is also well respected. 
I always buy from on-line specialists at most favourable prices. Suppliers inc. Tayna, Battery Megastore, and others. 
It is almost certain that the new battery will require coding to the car. 
Kind regards,

Gareth. 

[a6blacked007]

14 hours ago, Daniel9944 said:

Hi everybody have an A6 saloon from 2013 and have a very particular problem constantly. There are 4 error messages comes up literaly all the time: tpms system fault, parking brake, abs system fault, start/stop system fault. Now I took the car to 4 different mechanichs none of them knows what is the problem. One of the abs sensors come up as fault on diagnosticts but it’s been replaced twice problem is still there. They tried to clen the wires and the disc it made the problem go away for a month or so but it’s back since. What should I do where should I start looking?

thanks,

Dnaiel

I have same saloon 2013 same issue ... carista says right front abs issue on my 2013 2.0tdi haven't change it but it hasn't came back since a changed my front disks and pads 2 weeks ago but am sure it will ... 

 

Let me know if you sort your issue 

  Regards mark

Edited March 30, 2023 by a6blacked007

[bigtrv]

Hi.

I had the same on my Q5, the fault was an ABS sensor and replacing the sensor fixed it, but apparently a worn wheel bearing could cause the same fault with ABS, might be worth checking to see if yours is worn.

 

Edited April 2, 2023 by bigtrv
More appropriate

[Magnet]

Daniel has gone quiet. 

[a6blacked007]

7 hours ago, bigtrv said:

Hi.

I had the same on my Q5, the fault was an ABS sensor and replacing the sensor fixed it, but apparently a worn wheel bearing could cause the same fault with ABS, might be worth checking to see if yours is worn.

 

Just had wheel bearing replaced last week same side. 👍

[Daniel9944]

Sorry I’m still here, haven’t got the chance yet to take it to any service. It will be the 11th of April but there is so many possibilities that I don’t even know what to try… the sensor itself was replaced twice still same problem. Will update once I know more!

[Magnet]

No mention of the significance of a failing battery then Daniel-? 
Kind regards,

Gareth. 

[Daniel9944]

 

32 minutes ago, Magnet said:

No mention of the significance of a failing battery then Daniel-? 
Kind regards,

Gareth. 

Not sure to be honest, I have the car for about a year, same battery so far. One of the garages were able to reduce the number of the times warning light came up significantly with cleaning the disc and all the wires from the sensor, I think they were looking for a crack or disconnection but all seemed good. Anyway once they cleaned all that there was no light coming up for months. Now for the last month or two light are coming up all the time randomly.

[Magnet]

OK, 

Another possibility if eliminating the battery is not going to be considered, is the serviceability of the (usually) in-rear-hub ABS sender, rather than the sensor. 
Kind regards,

Gareth.  

[Daniel9944]

Well since checking the battery is easy enough that will be first thing to do. After that I’ll just ask to see jf wheel bearing are worn or need to be changed, or the disc. They mentioned if it’s not the sensor it could be a fault in the ABS system but this wasn’t investigated yet.

[Daniel9944]

So I’ve been at the garage yesterday, they have checked the battery, discs and pads, and wheel bearings all seems okay. Now there is one thing I missed to mention is that once I went tk another place they were looking for any sort of damage to the wires what connects the sensor to the hub all wires are fine but in the process they’ve cleaned the hub itself. After that I had no problems for about a month or so but it came back later. So I’ll be going back in two weeks time, get the hub cleaned again and if the problem waits off that might be it but until then we just go on the way we are. I’ll post update after my next visit!

[Magnet]

Thanks Daniel, 

The rear ‘senders’ - as opposed to the external electrical sensor - is built into the hub on our 2006 A3. This sender became weak  some years back and necessitated a new hub ( the bearing was fine). 
Same set up on yours?

Kind regards,

Gareth. 

[Daniel9944]

1 hour ago, Magnet said:

Thanks Daniel, 

The rear ‘senders’ - as opposed to the external electrical sensor - is built into the hub on our 2006 A3. This sender became weak  some years back and necessitated a new hub ( the bearing was fine). 
Same set up on yours?

Kind regards,

Gareth.

Unfortunately not exatly sure, but since the last time it worked it could be the cause of this whole mess. If that’s the case I’ll definetely will let you all know it might help someone in the future.

[Daniel9944]

Morning everybody, I have a little update here. I’ve been at the garage on Monday and they have cleaned the wheel hub on the front left wheel. Since then there are no warning lights coming up at all so far it seems like it has solved the problem but I’m still a bit worried that they will just simply come back some day. If they do they might have to change the hub it could be some small damage on it which is causing the ABS sensor to go off. If we get there I’ll let y’all know! Thanks for all the help anyway so far!

[Daniel9944]

Update again, lights all came back yesterday… no idea what ti do neither the garage has any…

[Magnet]

Hello Daniel,

Sorry to hear the issue has returned, but also sorry you don’t know what to do about it now. 

As I’ve said, if the sensor and wiring on the offending wheel are serviceable, then there a fair chance that the in-hub sender is sub standard and the hub needs replacing. This theory would be supported by the fact that cleaning the hub surface giving a (very) temporary solution.

Kind regards,

Gareth. 

 

 

 

 

 

[Daniel9944]

4 hours ago, Magnet said:

Hello Daniel,

Sorry to hear the issue has returned, but also sorry you don’t know what to do about it now. 

As I’ve said, if the sensor and wiring on the offending wheel are serviceable, then there a fair chance that the in-hub sender is sub standard and the hub needs replacing. This theory would be supported by the fact that cleaning the hub surface giving a (very) temporary solution.

Kind regards,

Gareth. 

 

 

 

 

Hi Gareth,

well the first time this seemed like a good solution as after cleaning the hub messages waited off about a month or maybe more to come back. But at this time warning are alL back after 24 hours unfortunately. 

[Magnet]

I’m not quite sure what you are saying Daniel.

Are you going to consider changing the hub or not? 
Kind regards, 

Gareth. 

[Daniel9944]

1 hour ago, Magnet said:

I’m not quite sure what you are saying Daniel.

Are you going to consider changing the hub or not? 
Kind regards, 

Gareth. 

Sorry I wasn’t clear. So the hub was cleaned once before. After that first cleaning all the problems and messages stopped appearing for about a month but they came back later on. Because that worked I tought this could work again and if that is the case that can possibly mean changing the hub would solve the problem for good. So for the second time the hub got cleaned this Tuesday and I was full of hope, but that same day the warning lights came on again. So this time cleaning the hub didn’t do any good. If your advice is still changing the hub I might give it a shot since nobody has any idea what could it be. I hope it’s clear now. 
 

Thanks,

Daniel

[Magnet]

No problem Daniel - I understood all of that before. What I didn’t understand was the earlier lack of mention of what had been suggested as a possible solution.

Kind regards,

Gareth. 

[Daniel9944]

1 hour ago, Magnet said:

No problem Daniel - I understood all of that before. What I didn’t understand was the earlier lack of mention of what had been suggested as a possible solution.

Kind regards,

Gareth. 

Sorry Gareth you mean lack of mention of possible solution suggested by the garage or here on the forum? Because sadly none of the garages I’ve been suggested anything at all! All the ideas were tried from this forum but nothing has solved the problem just yet.

Sorry I’m a bit clueless at this point especially since nct is coming up in less than a month and I won’t pass like that for sure…

 

Thanks,

Daniel

[a6blacked007]

Just to chip in all of my abs flat tyre message's arrived back yesterday. 

 

I was changing the gps antenna for a eBay cheaper unit successfully 🫡 all my wires behind mmi and air con were disconnected immediately got all abs errors connected all back up and just left air bag light on removing that with carista bit of a long shot but could that have been my issue or yours all errors gone again will report back if they arise again. 

[a6blacked007]

 

All errors have cleared ...

 

 

Must be some sort of wiring issue 

[Daniel9944]

19 minutes ago, a6blacked007 said:

 

All errors have cleared ...

 

 

Must be some sort of wiring issue 

I haven’t got carista but this must be a sign to get it, probably worth it in the long run. After the wheel hub was first cleaned an electrician gone through all the wires connected from and to the abs sensor looking for any damage but all wires were in good enough condition and they couldn’t find anything there. So again at the same place I haven’t got a clue where to turn. It’s really annoying but I’ll keep looking…