Massive abs errors

[Bg1]

Hi, 

 

Got some issues with my car that I cannot figure out what is. Please see the added pictures. I have tried changing all the sensors and I dont know what to do next. 

Ive previously had it at a mechanic who said he couldn't understand much because couldn't find problem with the ring measuring the speed. He suspected that there might be a abs control module fail. But he was really not sure. 

Anyone had any similar experience? 

Any help would be appreciated =) 

[cliffcoggin]

Bård.

It seems unlikely that there are various mechanical and electrical faults on three wheels at once so my guess would be a single fault in the brake module, however I can not be certain enough to recommend an expensive replacement. Another opinion here would be useful, or diagnosis on a professional Audi test rig.

[Magnet]

Hello Bard,

I think that you will find that the sensors receive their signal from the hub, which has a weak type of magnet imbedded in them. 
With the right diagnostic equipment, it should be possible to determine which wheel is at fault. Once you have established that, then you may find you will have to change the complete hub assembly, if you have already renewed the sensor with a good quality one without success. 
Kind regards, 

Gareth. 

[Bg1]

Thank you both for the replies😃

I've tried a little and I'm left with 3 errors. 00290, 00285 and 00283. Front left, front right, rear left. sporadic 003-mechanical failure. While doing live datalogging I can see that front sensors show the same (stable and consistent with speed). Rear left is unstable and jumps from 0 to same as front wheel. Rear right shows the double of front wheel (but is stable). 

I think maybe rear left is somehow "loosing the signal" since it's jumping. But I really can't understand the double speed on the rear right. What can cause the wheel speed read out to become double?