ABS module; noise

[nielstroll]

When you enter the subject in the search function of this forum, you count hundreds of entries. Just about all seem to go back to dodgy ABS modules or faulty sensors. Generally there is mention of the ABS and/or TRACS lights coming, or no mention of these lights.

I experience the same whirring sounds while driving, and the same racket while braking on my 1998 V70 AWD, however, my ABS/TRACS lights NEVER come on. And before you say faulty bulb or fuse, yes, they come on upon starting the car. Having no warning lights may not have any significance, but it would strengthen my confidence if I hear of many similar experiences.

[taxi]

My ABS-"tooth-ring-thing" (?) on my right CV-joint is not perfectly even all around, that is enough for my ABS to work when its not needed, in my case when braking at really low speeds. Good luck!

[jblackburn]

I'd start with cleaning the sensors and reluctance rings on the axles on each wheel. The front two are easy to get to; the back ones a little more difficult - so start at the fronts and see if it makes a difference.

I jammed mine up with a bunch of snow one year when I climbed through a snow mound in front of my car I was too lazy to shovel through, and my entire ABS/TRACS system started freaking out. It was trying to do traction control still even when I got out to dry pavement.

[Matty Moo]

If you have the right combination of cracked pins in the module, you'll get exactly what you are experiencing. The module thinks one of the wheels is locking up or slipping under acceleration.

Or, you have a wheel sensor issue.

[nielstroll]

To confuse you guys even further: when I touch the brakes lightly or hard, I get the abovementioned noise. However, often when I apply the brakes lightly at first, release, and brake again, the brakes operate normally, no racket, no squeal.

When all this started I thought about loose bearings, being kicked into touch by braking, but this has been eliminated as a potential cause.

Next week will see some action again, so remarks are welcome.

[nielstroll]

Thanks for all suggestions. Prime suspicion was on ABS sensors and cabling. Guess what: ABS sensors clean, electrical output measured, logged and OK, cabling in good condition, ABS module extremely unlikely to be culprit, as identical phenomena after replacement. Have now disconnected ABS cable, what a relief to hear no funny noises! No speedo, but use navsat instead. No ABS either, but drive defensively.

Some of the more weird suggestions, like battery malfunction, were checked and found not to be the culprit. There is some suggestion that the hydraulic pump might cause the problem, but I do not yet understand how. Any suggestions before I start looking for aliens?

[Matty Moo]

Realistically, you could check your pump motor but if it's making noise....it's working.

With everything you have, did you reseat your large harness that connects to the module? Sometimes it will take 2 or 3 reseats to get it on there perfectly.