Another wheel speed sensor issue
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Joined: Sep 2023
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2010 E350
Another wheel speed sensor issue
Tried a number of threads here but here is the basis of my issue:
1. Car went into limp mode with ABS/ESC fault
2. Scanned codes and got a right rear axel wheel sensor fault
3. Verified a lack of signal from right rear with a live reading (was zero, all other wheels reading fine)
4. Replaced right rear wheel speed sensor with a Bosch one
5. Cleared all codes and did a test drive
6. Faults came back on again almost immediately
7. Codes now read LEFT rear axel
8. Weirdly....live reading still shows no signal from right rear (was still zero, all other wheels still fine) but the right rear axel fault is gone and shifted left
So do I just replace the left sensor now? The fault returns after clearing on the LEFT rear each time I clear it despite showing a live reading when tested. I would replace it if the live reading showed nothing but no live reading on right after replacement AND the fault switching to the left while it still seems to be reading seems weird. I am a bit stuck and could use some advice. I don't want to just throw another part at it.
1. Car went into limp mode with ABS/ESC fault
2. Scanned codes and got a right rear axel wheel sensor fault
3. Verified a lack of signal from right rear with a live reading (was zero, all other wheels reading fine)
4. Replaced right rear wheel speed sensor with a Bosch one
5. Cleared all codes and did a test drive
6. Faults came back on again almost immediately
7. Codes now read LEFT rear axel
8. Weirdly....live reading still shows no signal from right rear (was still zero, all other wheels still fine) but the right rear axel fault is gone and shifted left
So do I just replace the left sensor now? The fault returns after clearing on the LEFT rear each time I clear it despite showing a live reading when tested. I would replace it if the live reading showed nothing but no live reading on right after replacement AND the fault switching to the left while it still seems to be reading seems weird. I am a bit stuck and could use some advice. I don't want to just throw another part at it.
MBWorld Fanatic!
Joined: May 2018
Posts: 6,600
Likes: 6,547
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
There was one member where his magnetic ring/strip on the CV shaft is the issue.
He replaced the rear right wheel speed sensor too at first.
Also to note that some "reading" could be substituted value by ABS module and not actual value from the wheel speed sensor itself.
A member here have seen this substituted value.
The real way to confirm the wheel speed sensor does produce a signal from the magnetic ring is to read it with a scope would be best.
If the magnetic ring/strip is a suspect, you can use magnetic field reader.
https://www.toyoheadquarters.com/thr...-bearing.2762/
Note, W212 magnetic ring is not at the wheel bearing, it is at the CV end.
This is W211, it is the same with W212
In EPC, it is called impulse ring. P/N A2303570182
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Wheel speed sensor signal
Good luck.
He replaced the rear right wheel speed sensor too at first.
Also to note that some "reading" could be substituted value by ABS module and not actual value from the wheel speed sensor itself.
A member here have seen this substituted value.
The real way to confirm the wheel speed sensor does produce a signal from the magnetic ring is to read it with a scope would be best.
If the magnetic ring/strip is a suspect, you can use magnetic field reader.
https://www.toyoheadquarters.com/thr...-bearing.2762/
Note, W212 magnetic ring is not at the wheel bearing, it is at the CV end.
This is W211, it is the same with W212
In EPC, it is called impulse ring. P/N A2303570182
=============
Wheel speed sensor signal
Good luck.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
You bring us a very interesting ABS wheel sensor issue.
You've replaced faulty rear right sensor then now the left side is ghosting...
The short answer is replace left side or perhaps try first to clean off any magnetic particles + oxidized connector.
It would seem as if fancy wheel sensors have the ability to loose magnetic sensitivity and EPS firmware learns the relative sensor levels to flag discrepancies.
As mentioned by @S-Prihadi sometimes new sensors actually require new ring installed, yours is different. It needs a pair.
You've replaced faulty rear right sensor then now the left side is ghosting...
The short answer is replace left side or perhaps try first to clean off any magnetic particles + oxidized connector.
It would seem as if fancy wheel sensors have the ability to loose magnetic sensitivity and EPS firmware learns the relative sensor levels to flag discrepancies.
As mentioned by @S-Prihadi sometimes new sensors actually require new ring installed, yours is different. It needs a pair.
Last edited by CaliBenzDriver; Jan 11, 2025 at 02:53 PM.
MBWorld Fanatic!
Joined: May 2018
Posts: 6,600
Likes: 6,547
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
This is the substituted value done my ABS module when one of the wheel speed sensor went bad.
Module did produce DTC, but also produced "substituted: wheel speed data for the wheel with the bad wheel speed sensor.
so becareful.
https://mbworld.org/forums/e-class-w...ed-sensor.html
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Bad magnetic ring at CV and lots of data, good read.
https://mbworld.org/forums/e-class-w...-lights-2.html
Module did produce DTC, but also produced "substituted: wheel speed data for the wheel with the bad wheel speed sensor.
so becareful.https://mbworld.org/forums/e-class-w...ed-sensor.html
---------------
Bad magnetic ring at CV and lots of data, good read.
https://mbworld.org/forums/e-class-w...-lights-2.html
