rRambo

Hey everyone

By way of background, I have a W220 S430. I bought the car about 9 months ago and since day 1 it's felt like the brake discs/rotors were slightly warped.

About 5 months ago, the car's ABS started kicking in at low speeds. Very quickly it got worse and the ABS would also kick in when I wasn't pressing the brakes until eventually the BAS/ESP/ABS warning lights all came on and the ABS stopped. I took it to a local independent Merc garage and was told that one of my wheel speed sensors was faulty so this was replaced and problem solved.

Recently however I've noticed a similar issue - namely, it feels like the ABS is kicking in at low speeds (10mph or less) as there's a noise and some pushback on the brake pedal. It sounds exactly like this guy's car ( ) It's been happening for the past couple of weeks however yesterday when it happened the ESP warning light flashed a couple of times before the BAS/ESP/ABS lights all came on and the ABS stopped kicking in.

Basically what I'm wondering is, are the warped discs/rotors causing the ABS to kick in or interfering with the wheel speed sensors some way? Or is it just bad luck and another one of my wheel speed sensors needs replaced? I've booked the car in to have my front discs/rotors replaced but I was just wondering what people thought before I take it in?

Thanks in advance guys.

rrambo

lganski

I would replace the other speed sensor. Warped rotors should not affect the ABS.

jnash

Are your tires evenly worn or might you have one that is newer or badly worn compared to the others?

VMAX7

Make sure your tires are exactly the same sizes on both ends.

Front R and L need to be the same: eg. 225/60/16

Rear R and L need to be same: eg. 225/60/16

If you have any variation in size the abs will go crazy.

Are you 4matic?

rufusjack

I am having the same issue. Mine started right after I had four new tires installed (correct size) and having both front lower control arms, wheel bearings, and ball joints replaced. My chasis number is less than A294500. http://www.autohausaz.com/search/pro...@Control%20Arm

Thoughts?

rRambo

Mine turned out to be another broken wheel speed sensor. Had it replaced and the abs hasn't malfunctioned since

rufusjack

Any ideas on how to figure out which one is bad? Any chance one cold have been damaged when my mechanic did the work that he did?

Jack_88

Damage to sensors, wires, corrosion or debris in electrical sensors. The ABS sensor was disconnected and moved to replace the ball joints, so damage could have very easily occurred if he wasn't careful with either the sensor or the wiring and connector. I think you will need Mercedes software and hookup to diagnose it exactly.

Bill Rodriguez

Rotors had worn thin.Replaced and fixed