Marcelo1

Hello. I read a few threads here on this issue. I have a question about the ABS sensor itself that may be the problem....

I drove the car a few weeks with a subtle front bearing noise (the shop told me it was ok, my tires were noisy) until the bearing overheated on my way to work one day. The grinding noise then became very loud, so I stopped the car within about 50 yards, the ABS/ESP malfunction lit up on the dashboard and went out to take a look. The front right wheel of my 2007 E350 RWD's dust cap and the little plastic hubcap had exploded off from the heat (and were never found) and I saw some smoke coming out of my bearing for a minute. The grease that was visible looked black. I did not drive any further and towed the car to the shop.

I had the bearing replaced today at the shop and the ABS/ESP malfunction code was erased and it quickly returned after driving about 100 yards. Here is my question: "Is my ABS sensor bad?". The ABS malfunction appeared before I even took it to the shop, so could the ABS sensor have got cooked and damaged from all the heat? The mechanic did not mention that he had seen any visible damage to the sensor. Could the heat have caused the magnetic seal ring to get cooked to trigger the initial ABS malfunction (and my ABS sensor could be still good?). I though the ABS malfunction had come after the heat friction had seized the wheel a bit and and the ABS sensor had picked up this spin difference compared to the other wheels, but who knows?

Since the work now got done by the shop, some new variables could have been introduced, ...the shop could have installed the magnetic seal ring backwards, the shop could have used a seal ring that was not magnetic (is this even possible?) since they usually don't use OEM parts. I am trying to figure out if I should just buy a cheap ABS sensor from German Parts Saver so that I can have the part ready if needed, as it took them a few days to get the bearing delivered and my car sat in the shop waiting for this unnecessarily. If they screwed up the magnetic seal ring installation and they need a new one, it will take them a day or two get one delivered. Maybe I should just get one of these as well, any ebay recommendations for where to get a magnetic seal ring that works for sure, just in case?

Heguli

Do you have acces to a scanner, like iCarsoft MB or similar? I used my iCarsoft to diagnose ABS issue, and I could read the sensor to ring gap. It was borderline being ok/not ok. I bought a new ring/wheel seal, and replaced it, issue solved. I would look into that before replacing the sensor. Might be just set too deep.

Marcelo1

Thanks. The mechanic used a hand scanner to reset the code that was slow and not too helpful, and he told me to bring it back next week to hook it up on their main shop scanner (maybe he figured his tech messed up the seal install and needs a few days more to get a new one on order?). I was not aware that the scanners are able to read the gap. I am suspecting they drove the magnetic seal in too deep instead of just getting it flush with the hub.

I am coming in next week with a seal and a sensor I bought on my own as it takes a few days for them to get their parts and my car just sits in the shop. I got a Febi seal for $20 and a sensor for $15 so I am not spending too much here and this way, I can get the issue resolved the same day and get my car on the road faster.

Marcelo1

Which model of iCarsoft do you have? There are basic under $100 and the more advanced ones beyond that. There is a Mercedes V3 that looks like a nintendo gameboy that I though was their best, but people are also selling an I980 model that claims to be the professional model.

Heguli

Me neither. I was driving back and forth on our shop backyard, reading the speed from the sensors. They were all close to each other, but then noticed that I could read the gap. I thought that since the speed shown is good, gap is too. But no, right front was faulty. I bought a cheap aftermarket seal w/magnetic ring, and it fixed the issue. There was a small play on the wheel bearing, but IIRC it didn't affect the gap whether I was curving left or right.

I have iCarsoft MB V2.0.

Marcelo1

I bought an icarsoft V3.0 and I read the codes related to the adaptive brakes. I had the 2 codes below. I could not figure how to check the gap. Does code 2 indicate the ABS speed sensor is bad? That would be easy to fix that having to remove the hub and replace the magnetic seal ring.

Code 1:
7284
State: Historic
Check Codings in Control Module N93(Central Gateway Control Module)

Code 2:
4457
State: Current and Historic
Test: L6/2(right Front Speed Sensor), Rotor

Marcelo1

Solution: The car needed a new spindle assembly as the heat generated had probably damaged the original one (probably warped the spindle out of center and would not allow the magnetic ring of the seal to properly meet the wheel sensor to generate a signal). The old spindle also had some parts of the bearing bind to it and needed some sanding to clean it up, this did not end up working and a new spindle assembly needed to be installed. they also threw in a new complete Febi hub with bearings included from their factory and a new wheel sensor and it all worked nicely on the first try.