Need VAG com experts!

[jkern]

ok here is my problem: my ABS has been activating at slow speeds for the last 30k miles or more. i have cleaned the sensors multiple times, i have replaced two of the them that looked suspect, i have replaced one tone ring/cv joint, had the ABS module rebuilt cause it was flashing the light at me. after all of this it still does it at every stop. i have a VAGCOM tool on my laptop but there is no error code set in the ABS module with an intermittant or anything. So the question is can i use the vag tool in real time (driving down the road) and look at the sensor readings to the ABS module and see which one(s) is causeing the problems? if so, how?

the car is an early build 98 1.8t quattro 5speed.

it is getting completely annoying and i hate spending $140/each to replace sensors.

-jkern

[MattzWarsteiner]

Hey JK, yeah those little things are not cheap. Hope you kept the old ones.

Open up the measuring blocks 1-4 and the wheel speed sensor data is here. You could do a data log from here and analyze the results after a drive.

Couple of things to also check on this low speed ABS engagement:
Tire pressures and height < must be equal or nearly so.
Connections to both the ABS output (under the hood) & the control module (back seat)
Ground connection to the output module.

[djwimbo]

If you have VAG-com you can monitor the WSS's output to module. If you don't you can use a wiring diagram and check them all from the connector at the module. That will test the sensors and the wiring all in one.

It's possible that the module is mad at you. I hear it's a solder in the module itself that burns up, but don't quote me on that one. They're not real hard to remove. We have somebody rebuild them for ~$140.

[jkern]

already had the module rebuilt...didn't fix anything but the ABS light that was flashing at me. thanks for the thoughts...

does anyone have any specs on the sensors to tell if they are good or bad?

[MattzWarsteiner]

I recall checking mine and the ohms reading was in the thousands - 1-2K IIRC. You could put the meter on the harness connection at the module (under the back seat) and monitor it while manipulating the wiring to the sensors to see if there is an intermittent short/open circuit.

The VAG log of your wheel speeds may help locate the bad wheel if that is the cause. (tone ring, wiring,sensor)