Abs sensor problem need help !!!!

[Xavier19]

Hi Guys,

Need your input on a problem I got on my 2011 BMW 328I X-Drive.

I got a fault in the dash with ABS/DSC and red brake light.

Scan the car with Ista and I got a fault for both front ans/wheel speed sensor direction of rotation.

I went and do the test plan and run with the car, basically when going forward the 2 front show reverse and the 2 back showing forward.

I replace the sensor 3 time with no luck.

People were calling the ABS/DSC module i replace it 2 times the whole unit and code it with Insta no luck.

I still have the same fault the 2 front wheel abs/speed sensor when im going forward and showing that IÂ’m going backward.

Im at lost here what else could cause that kind of issue ????

[dworthy]

Welcome to the Forum!

So BMW's don't like after-market sensors, IIRC Bosch is the supplier for that one. Next will be to look at the impulse ring using a borescope. On the E-9x, it will be part of the bearing, so if you see a large piece missing, time for a new bearing.

Next step will be to test the wiring from the Module to the sensor, any breakage will cause issues.

[drewusmaximus]

I got the infamous trifecta lights. The scan said rear driver side ABS sensor, but it was the wheel bearing all along. I replaced the sensor, same lights returned. Replaced the sensor with a new sensor from Amazon and wheel bearing and lights are gone. Still going strong. I suggest replacing the wheel bearings. They're probably original. It's not hard to replace, as long as you have the correct tools. Or pay an Indy 300 for each side. I was quoted 280.00 for the rear driver side. The abs sensor cost me 25 bucks for a pair, wheel bearing from 1A Auto was 30 bucks, gear puller for 15 bucks on Amazon, M27x1.5 axle nut for 6 bucks on Amazon, but I did buy a wheel bearing press removal kit for 50 bucks (must have!). Add all that together and it's still cheaper than what I was quoted for one wheel, but I can do all wheels myself. A small investment to save a lot of money. I even replaced both rear wheel bearings on my Ford Escape with ease. I digress.. I think it's your wheel bearings. Keep us updated..

[JDStrickland]

I'm confused. Wheel speed sensors don't know forward and reverse direction, they only know the relative speed of rotation. The sensor sees the tone ring go by and make a pulse. The computer looks at all of the pulses from each wheel and decides that all wheels are going the same speed, or that some of the wheels are going faster or slower, or are stopped, and the computer then decides that corrective action needs to be taken.