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Front left wheel rpm is intermittent - ABS unavailable

2155 Views 10 Replies 3 Participants Last post by  Ivan Kocher
Hi all,

I have a 2008 ML320 (164.122), were ABS/ESP says it is not available. I already replaced ALL rpm sensors, but front left wheel is still strange.
I have a iCarsoft scanner, and if I read ESP -> running values -> rpm sensors, I can see that all four report speed, *but* front left speed is strange, goes up and down as the wheel turns, while the other three wheels show a 'constant' speed. I have done the test at multiple speeds, from 10km/h to 40km/h.

If I reset the errors in ABS/ESP, and start driving the car, the front right wheel brakes get engaged like crazy, kind of expected, as ESP sees left wheel "stopping".

Currently, I am thinking that the magnetic ring might have some damage. The car was bought used 2 years ago, and was until one month ago that the ABS/ESP & front wheel problems started. I also discovered that it had a frontal collision of some type, cause I discovered a few mis placed/ broken parts while changing the rpm front sensors. Has anyone seen something like this before? I know that the wheel bearing comes with the magnetic ring.

Any suggestions?

I already read the thread " ML320 CDI ongoing self braking problem??? ", but does not look like my problem.

1 - 5 of 11 Posts
First you indicate that the L/F wheel wasn't showing correct values, then you say the R/F wheel is locking up. Is it still correct?
When you say locking up, what do you mean? Does it pull to one side, are the brakes hot?
Every thing depends on the highest scale on your torque wrench

Using your T-rench at its highest scale, then remove the socket and attach it to a heavy breaker bar and tighten it a1/2 turn more.

At the bottom of the pdf are the torque values and as you can see 250Nm is way off the mark.


I do not want to be pendantic, but looks like the pdf is for a w163. Also on pag 4 of your pdf says 490Nm for the axle nut ...

I agree that the 250Nm is pretty hi.
That's the torque. I didn't make it up.
I posted the correct PDF and guess what, the torque is higher.
1 - 5 of 11 Posts
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