Abs faq
 

Hey Folks! I have attempted to locate a decent primer or FAQ re: the A4 (B5) ABS system.

I got a situation where my front R brake goes into ABS chatter-mode for no good reason. The system in general seems to work fine on ice or snow, but the FR brake kicks in on dry / no reason stops. +- 60% of the time. More often on slow stops than on hard braking. I -Think_ I have a bad sensor.

My Google-Fu has failed me. Haynes is useless.

I also have the Bently phone book sized guide and it tells me how to replace all the components, but I have not been able to find out how to diagnose the issue.

I have read that I should check the resistance on the sensor, and I can do that, but for the life of me I can't find the values expected to confirm or dismiss the sensor as the problem.

I have a shade-tree understanding of ABS operation, but I am looking for a diagnostic guide specific to the A4 Quattro B5. Surely there is one one the net somewhere. Please help me find it :)

Thanks again guys!

Peace,

Jon

Sometimes that can be fixed by just cleaning the sensors and reinstalling them. But you have to be careful you don't break them getting them out. Have you pulled the codes to see if you have a bad one? Read this page for an understanding on how the sensors work.

http://www.sjmautotechnik.com/troubl...ing/brake.html

Good Luck...

It could also be a cracked tone ring on the axle. Clean the rust and dirt out and inspect the axle.

Thanks for the responses. Esp the trouble shooting guide.

There are no ABS codes from the B5, as far as I am aware, or have been able to find. That would sure help :)

Peace,

Jon