I can't believe in the last week I have gotten no information on this topic. Possibly, it is not anything anyone has had to deal with, but I can't believe that.
This is what I have (painfully) determined from the Mercedes 129 wiring CD-- My 92 500SL has a total of (4) speed sensors (VSS). The 2 in front I have tested (1000 ohms nominal with a small inductive a/c current when I turn the wheel). There are (2) sensors in the top of the differential that can be interfaced if you drop the differential. I can measure a nominal 750 ohm resistance on connector E of the multi-pin connector by the fuel pump under the car just to the passenger's side of the car and (according to the wiring schematic), on connector portion D, I can measure the mag pickoff also. However, I see an open circuit on the 2-pin connector D.
This whole diagnosis is the result of an ASR and ABS light on after the car has been started and starts to move. The battery voltage is new (12.5 volts, and 13.9 volts when the engine is running). I also have determined that the wiring harnesses are NOT the defected ones...that took about a week of no one knowing that this 129.066 (9/91) did not have these bad harnesses.
Please confirm: there are (2) inductive pickoffs mounted to the top of the differential; I have to drop the differential to get them out; there is no other wiring/??? problem that I am overlooking.??

Thanks in advance for any information you can provide.

Cordially

..as alway, I apologize if this topic has been covered, but I apparently don't know the search terms. If you do, possibly you can provide them.

 

Did you ever discover the fault source?