Seaquesta

I have a fault with the my front wheel sensors that hasnt been the easy fix i hoped for and hence I'm hoping someone can shed some light on the problem and a possible fix.

Background
An ABS, ESP and runflat inoperative error popped up on the dash of my w204, so I plugged in the icarsoft MB2 scanner which told me the two front wheel sensors were not providing data - so far so good, but it seemed strange that both would fail at the same time. So i ordered two new replacements which duly arrived, and after viewing a youtube clip, I replaced the left side sensor and tried to clear the error - but no go! the error was still there and after a short drive, still would not clear! I then went to replace the right side sensor but discovered that this sensor is slightly different from the part i ordered as it has a brake pad sensor incorporated which the replacement didn't, hence i left the original part in place. However it seems very odd that the newly fitted left side sensor hasn't fixed the problem and I'm suspicious that the sensors aren't the issue anyway and hence i doubt replacing the right sensor would solve the problem.

Does anyone have any idea on whats going on here? it appears there is a problem affecting both front sensors, but not the sensors themselves.

Any info or insight would be much appreciated

Incidentally, the rear sensors are working fine.


As a side note and possibly related, I'm getting fault codes "C327100, C326600, C110700, C111700 This fault code is not found in the database" as well as the above sensor messages - related?

Urueyeprecious

Seaquesta

Yes I have. It turns out that the two Bosch front wheel sensors i imported form the UK to New Zealand where faulty. Once I installed a locally sourced genuine MB OEM wheel sensor (at significant cost of NZD$250!) the problem was solved!
I don't know why the Bosch units wouldn't work and i haven't had a response for the seller when i raised it with them - perhaps the Xraying at the NZ boarder causes an issue?!?!
.

Urueyeprecious

Urueyeprecious

allera

Ref 2013 GLK350 45k miles RT Front Wheel Sensor Issue



Weirdest thing I went thru an automatic carwash one that I’ve been thru any times before and just as I was exiting the carwash my GLK went into ABS Fault never seen so many lights on my dash before. J

I did some research and purchased the ICarsoft MB V2 to trouble shoot the fault for about $150. The MB V2 worked great it identified the rt front wheel as the problem and showed no signal coming from that wheel sensor. I was able to clear the fault but obviously it came back since the problem had not yet been fixed.

I looked for the best price on a replacement wheel sensor and found the best price at partsgeek.com paid about $35 plus $8 shipping for the part a ( Brake Mercedes GLK350 Holstein ABS Speed Sensor Holstein 2ABS3185 ) That’s when my problems really began.

After installing the part not only was my issue not resolved but now I couldn’t even clear the fault. After numerous emails back and forth with ICarSoft tech support (they are great by the way) I started to suspect an issue with the analyzer and considered returning it. Instead I went back and reinstalled the original wheel sensor, the faulty one. After I did that I was now able to clear the fault again, but it returned since this wheel sensor was already shown to be faulty.

After seeing the post by “Seaquesta” indicating that he had issues that were not fixed by replacement Bosh sensors, I purchased an OEM sensor from Mercedes installed it and the problem was resolved.

I will add this I took some readings on both the faulty sensor and the replacement OEM sensor and to my surprise readings were almost identical.

Both Mercedes sensors had a resistance of 6.2 Meg Ohms (in one direction) when I reversed the leads both sensors read open. Also a YouTube video indicated that rotating the wheel with the sensor installed should generate some small AC voltage that can be read on the sensors pins. I tried this on both sensors and neither the new from Mercedes or the original faulty one generated any voltage.

BTW The readings on the part I received from partsgeek.com were totally different the ohm readings were about 2.2 meg ohms and the polarity was opposite the polarity of the Mercedes part. I returned the part to partsgeek (had to pay return shipping) and hope they will refund the purchase price.

Juan Moreno

w204 same issue I did notice my front passager speed sensor is reading faster then the other 3 so I'm guessing it's gone bad hopefully I will change it out today hopefully it fixes my problem also notice the air valve sensor came on the side front passenger but that went away I'll keep you updated

JMckW204-C250

Thanks for all the great info, new to this forum and already benefiting a lot from it.

I also had exactly the same problem as detailed in the original post, same fault codes etc.

So I too bought an iCarSoft MB ii and plugged it in. Not having used one of these diagnostics tools before it was a bit of a learning experience, but i figured out how to look a tthe 'live data streat' from the wheel sensors and it appears that all four wheel sensors were reading exactly the same speed when the car was at a stand still, and when i slowly rolled the car forward, all four sensors reacted similarly and speed went up. Which suggests that all four sensors are actually ok and maybe just gave a bad reading once. So I've cleared the fault and so far haven't seen the fault again (ABS/traction control etc not operational).

I should also mention that on one of my google searches regarding this fault that I read that a steering angle reset or something can fix the problem. When i then googled how to carry out a steering angle reset, they said while the engine is running, simply turn the steering wheel all the way to the right, then all the way to the left, then back to the centre". I did do that, but i honestly can't imagine that it did anything at all. Surely no fix could be that simple.

Anyway, for now my faults have gone and am considering returning the two genuine MB ABS sensors i purchased from MB last week and saving myself £146.40 and also the time it would take me to remove the inner wheel arch lining and replace the sensors. But something tells me there's a good chance the problem will come back and i'll be replacing them in the not too distant future!

Thanks again for all the great info guys.

W204 - C250 estate 2012 diesel

Paul Sumner

The sensor on the right-hand side looks different as it incorporates the brake pad wear sensor. However, when you remove both sensors from the plug the wheel speed sensor and the brake pad wear sensor come apart.