Abs traction control and shuddering
 

Sometimes my abs and tc light come on around 70mph and stay on until I turn off engine then they clear. Have just replaced a bearing by my local mechanic on nsr wheel. I am also getting a bad shudder when I pull away now also. Any ideas what this could be people? Been told it could be the dmf but I'm sure it was ok before bearing was done. Have literally only just got the car amd can't remember it doing it on the test drive.

Cheers all

Also scanned it today and it bought up steering angle sensor and coolant temp sensor. That is all.

Scan the abs. Might be a dirty sensor. Possibly the one where you just did the bearing.

They may have accidentally broken the sensor.

A few thoughts:

- What exact model do you have? I have a 2001 A4 1.8T and that model doesn't even have a steering angle sensor. I'm curious which B5 model does. The S4 maybe?

- Did you scan the ABS module itself? If it's going bad it should report errors. Bad ABS module is VERY common, search the forums. You can take it out, send it out to get fixed for $50, and re-install. No problems driving with it out, you just won't have ABS.

- I was having weird ABS problems at one point even after fixing it, and it turns out my alternator was dying and the voltage wasn't high enough. Low voltage can cause all sorts of mysterious problems like that.

When you say "bad shudder" is it actually firing the brakes?

If the light comes on at speed it's likely a sensor is dirty or has metal shavings stuck to it. If you don't have a vagcom or any way to scan it then spend some time to clean the sensors one by one. Take the most powerful brake cleaner you have and blast the area between the axle and hub from the backside, then spray some compressed air into there. Repeat once or twice more per wheel and concentrate on the area where the sensor is. If that whichever sensor is bad.