Originally Posted by Pavka007

I will make a wild guest here but if you are talking about your 300E perhaps I can point you into the right direction.

On the rear drive shaft (both sides) close to the tire side there is a RELUCTOR ring. The purpose of it is to read the magnetic field. You can buy them aftermarket. Mercedes will tell you that you need the whole drive shaft, YOU DON'T. You can fix this yourself inside 75 minutes, I've done it on W124.

The wheel sensor works by detecting a change in a magnetic field as a tooth passes it. This is seen by it as a pulse in the signal that it produces.

The Reluctor rings with the holes on are an aftermarket item designed to fool the sensor. The holes are aligned to fit over the gap between the teeth. It is the teeth rusting away that causes the problem. As a tooth rusts away the change in the magnetic field as it passes the sensor reduces and the pulse becomes less.

As there is more metal around each hole the sensor detects a change in the magnetic field similar to a tooth passing and a pulse is generated.

Perhaps you have notice that I am talking about TOOTH and RINGS, the reason is simple, original Mercedes shaft is with teeth and the ring is looking like bracelet with holes.
A lot of W210 back in the UK have this problem because of the rain and salt on the road and they have all the lights on BAS, ABS, SRS as soon as the ring or rings are replaced everything is as good as new
I am sure that someone here in the US make them, but when I had to deal with it I've contacted a company in the UK and everything was done inside 4 days.
Have a look for yourself and check your rings. If you need someone to buy them for you from the UK and forward them to your address let me know I will help you with that if the company say that they can't post overseas. Just one more piece of info, all of the E-Class are the same size, so u can order any of them, it doesn't matter. I will ask a friend back in the UK, he was telling me few weeks back that he replaced one of them but he got 2 rings, so if he still have the second one, you can have it. for cost price plus shipping.


Good luck