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View Full Version : Repaired my ABS module, all lights are gone but I have the same grinding at low speed



4A Play
01-13-2017, 08:35 PM
So I had the dreaded grinding in the brake pedal at low speeds and ABS light constantly on. I pulled and micro soldered my own ABS module and plugged it back in. All codes are gone, no ABS light on dash, No BRAKE light flashing at me. All appears well until I attempt a low speed stop.

The brake pedal pulses and grinds. This ONLY occurs when I have the ABS fuse in place. If I remove the fuse this pulsing is gone but the dash lights are on of course. I scanned it for codes with a handheld scanner and have no braking system faults.

Im guessing this is a wheel speed sensor failure and found them for about $35 online. But I was unable to find the exact symptoms of a bad speed sensor through searching. Does this sound like a ABS wheel speed sensor issue?

Thanks guys!

mfdk
01-13-2017, 09:48 PM
Do a little search you'll fine my find my thread about this issue, it was the rear ABS Sensor Tone Ring.

4A Play
01-13-2017, 09:59 PM
Do a little search you'll fine my find my thread about this issue, it was the rear ABS Sensor Tone Ring.

Excellent, sounds like similar issues going on with my 1.8. So do you think it was the speed sensors being dirty or a combo of replacing them and dirty/ clean tone rings? I actually just found OEM sensors on closeout for $8 each [o_o] and ordered two for the front. Figured I might as well replace them at that price. Hunting for cheap rear sensors or Ill just clean them

mfdk
01-13-2017, 11:29 PM
I fought this issue for almost 4 months and i found out that no matter how dirty that sensor may get it still works, using vcd i can see that my sensors were just fine so instead of repacing sensors "genuine" expensive as hell i went the tone ring based also another vw forum and sure enough it was the tone ring, even though you could hardly seen anything wrong with it, it did have a little dent on the tone ring lines.

Quattro420
01-14-2017, 04:14 AM
Befor I personally would replace any parts I would install vcds and watch your wheel speed data. It sounds to me like one Sensor is cutting out almost at a stop, the computer sees thee wheels spinning at 5 kph and one wheel goes to 0 kph the computer sees that and thinks the wheel is locked up / sliding and then applies the abs to prevent wheel lock up, but in all reality no wheels are slipping. My 01 1.8t did it turned out it was the left rear wheel, I removed speed sensor cleaned were it sits and re installed it no more abs activation unless I'm really slipping. The rust builds up under the sensor and raises it up just enough to change the gap between the tone ring and the sensor.

pkfinn
01-15-2017, 06:03 AM
When the ABS activates, do you get any indication, like a light or something? My 99.5 A4 feels rough once I slow to 25 or slower, but no ABS light or anything. I attributed it to the drilled and slotted rotors that are on the front. Maybe it's the ABS activating?

Davdraco1
01-15-2017, 08:15 AM
I had my ABS module go out on me, normal lights in dash. Replaced it with a used one. Worked fine, no codes. About a month later I would have the abs always engaging so I brought it to a friend and he said he hooked it up to a computer and fixed it. I have no idea what he did. But I do have my abs light on for a rear drivers wheel speed sensor. I don't think my abs works right now. Should it still work if I have a bad sensor?