You have pulling the cable hard then if show it open circuit that mean you have a bad sensor (good sensor will not open) more then 80% of ABS problem is wheel speed sensor.

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MB STARS Master Guild Technician,17 years MB tech
14 years independent shop owner

OK, thanks.

I'll take off the sensors and measure again.... if open I'll replace. Strange that both read almost the same..... left is 0.9 ohms, right is 1.0 ohms. The upper limit of spec is ~1k ohms and the lower limit is 0.85 ohms - so both are near the lower limit as measured before removal. It sounds like they start life with a higher resistance value when new but degrade toward open with age and/or use.

Should I also take off the rotor and clean the hub ring that the sensor reads?

Frank

Very nice! After removing the front sensors at the wheel and cleaning them, the right front measured 1.057 ohms and the left side (where the noise appeared to come from) was OPEN! So, I guess the meter was reading the buildup of particles before I removed them and cleaned them.

Question: Should I replace both sides since the left is so close to fault limit or is that still good for a while?

Frank

That is a good idea to replace both side sensor at the same time.
107 540 02 17 for left side 107 540 03 17 for right side both list for $123.00 check with FastLine at the top of page.

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MB STARS Master Guild Technician,17 years MB tech
14 years independent shop owner

Thanks again! I think I'll also replace the rear so all will be new. Local dealer gives me a small discount depending on price. In this case it 10% on a list quote of $120 ea. for the fronts and $116 for the rear which nets to $108 ea front and $104.40 for rear - quite a bit less than FastLane, but I hadn't noticed their ad until you mentioned it.... good source to know about. I saw they were $100 higher on the heater blower than Adsit. I was curious because I just ordered one from Adsit for about $350.

I'm also going to replace the wear indicator cables because the insulation is cracked, but I can't believe how difficult it appears to remove the cables from the grommet. That looks like a real PITA nightmare. I'm hoping the dealer can get them already assembled as a pair so I don't have to deal with pulling them through the grommet.

Thanks very much for your help!

Frank

Brake sensor cable you have to remove wire from the connector then through the rubber gormmet is not that hard. have fun

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MB STARS Master Guild Technician,17 years MB tech
14 years independent shop owner

After waiting for MB to ship all of the misc. parts from Germany - and still a few minor replacement parts out of stock - like one of the sensor wire clips at the brake hose connection, I went ahead and replaced the master cylinder & reservoir, both front ABS sensors, both front brake pad wear indicator cables, all four brake hoses and ran about 4 quarts of fresh brake fluid through the system to flush to clear color. Also replaced the heater blower while waiting for the brake parts.

Many thanks to "MB Stars" for your helpful advice!! She's once again "The Beast" that she always was!

Frank