ABS kicking in without me touching the brakes

Lately, when I make a slight turn at fast speeds (i.e. freeway exit ramp), my car makes a sound like the anti-lock brakes are kicking in without me even touching the brakes. This doesn’t happen all the time and can happen on the smoothest/driest of surfaces. More confirmation of ABS kicking in is the fact that the car slows down when I hear the noise.

I took the car to the dealership to investigate/fix this noise. The dealership said that the cause was uneven tread wear on the two front wheels (5/32 difference). This sounds like bologna to me. What do you think?

P.S. the car is a 2006 VW Jetta 2.0T

Sounds like you could have a worn front wheel bearing…or…the main axle nut that holds the end of the cv joint to your wheel hub…could be loose…thus letting your wheel bearing/hub to deflect a lot more than normal…this would make the rotor rub into the brake pads etc. In either case the loose axle nut theory needs to be looked into…its easy enough to check really. The wheel bearing issue SHOULD make a constant droning noise… Bearings usually warn you when they are going bad.

You can jack up whichever side of the car you wish…Hell jack it up in the middle and when both front wheels are off the ground grab either of the front wheels at 12 and 6 o’clock and see if the wheel will deflect…then try it at 3 and 9 o’clock…see if you have lateral deflection as well…

ACTUALLY now that I thought about it a bit more, if you have uneven tire wear, you could have a worn suspension bushing/s, worn tie rod end or a worn ball joint… I think you should start at the wheels, then the suspension checks…and work your way out to the axle nut…if you ever get to the axle nut without first finding the issue elsewhere… Thats about all I can think of…

Blackbird

You should pay attention to all of what HB said. I would add that I have heard of this issue before in terms of uneven front tire wear. I also believe I may have had that issue once. I used to get an occasional low speed (near stopping) ABS engagement on a van I have. It didn’t happen all of the time, but I did have one front tire worn more than the other and it hasn’t happened since I’ve gotten new tires. Of course, I also had to replace a wheel bearing also, and my speed sensor are integrated into the hub with the bearings. So I can’t say - tires or wheel bearing - but it must have been one of them or both.

You can temporarily remove the ABS fuse to eliminate that possibility…

I take you at your word when you say fast speeds and ask, do you have stability control? That activates the brakes using the abs to prevent your car going into a skid. Making turns at fast speeds would easily qualify. The car slows down when the throttle is cut automatically too. Uneven tread wear which occurs on fwd cars while turning with the throttle on, could be causing a slight, in perceivable skidding while turning which activates the system. I’m with the dealership and won’t second guess them. A difference of 5/32 inch is A LOT. Especially on the same tire. If on The same or even different tires, front to back, your car will woefully understeer with worse steering traction on front which could ecaserbate this skidding. My guess is that it will lessen dramatically if you rotate the tires and slow down before turning.

Remember wheels turn at different speeds when corning, the inner wheel slower and outer wheel faster around a corner. Driving straight with 5/32" difference you are running wheels at different speeds, now you compounded the fact by having differing tread.

Running the wheels at enough difference in speeds is the input the ABS/traction control/stability controller use to kick the system in action. I believe you hit the thresehold.

EASY FIX replacing a tire or pair of tires across an axle. Where you hoping for a more complicated solution?

Do you have stability control? Maybe it’s trying to save you from a spin. So maybe the dealer is right too.

The ABS will not activate unless you apply the brakes. TCS, if you have it, will.

“Uneven” tread wear includes conditions such as scalloping, feathering, and a number of other anomolies. The noise itself is probably coming from the anomolous wear. Other posters have suggested possible cause of the anomolous wear. Soomeone need to get the car on a lift and evaluate the condition of the chassis components and check the alignment.