brett at cloud9.net
Wed Jan 16 16:46:44 PST 2008
On Jan 16, 2008, at 10:50 AM, gordy.schesel wrote:
> One of my 91 quattros is having ABS chatter when braking to a stop
> on dry
> pavement. Odometer has 240k miles. Is the problem corrosion of one
> or more
> wheel sensors?
Chatter at low speed is caused by low signal to noise ratio; the ABS
controller has trouble "seeing" the electrical peak from the sensor
passing a tooth on the hub wheel, and starts to mis-read where the
tooth actually is, which causes it to think the wheel has changed
speed, particularly at low speed.
Causes can be any of the following, I believe:
*Improper spacing (fix: reinstall with new ablative caps)
*rust on the hub teeth (clean, protect with some sort of paint, maybe
*bad ABS sensor
I may be confusing them with flywheel sensors, but I think filings can
accumulate on the head as well?
More information about the 200q20v