Understood re: ABS vs. 4Matic.

If you happen to know the correct voltages for the sensors, or can point me toward schematics with this info, that would be greatly appreciated.

I'm assuming the sensors are going to be located somewhere near each corner - on/near axles/CV joints up front I presume? (early unscientific 'testing' suggests that left front is the source).

Also - additional info or potential red herrings - simulated panic stops last night (dry pavement, standing on the pedal from 60mph down to 20mph) did occasionally result in brief (maybe 1.5 - 2 second) lock up of one wheel. Seemed to be left front. New General Altimax tires (less than 500 miles), dry clean pavement, straight road, 80*F air temp, probably +10 at the street, tires well warmed prior to 'test' was executed. Repeated half dozen times, got quick squeal twice.

__________________
1961 220b: first project car - sold.
2000 CLK 430: first modern Benz - sold.
2001 CLK 55: OMG the torque!!! - sold
1972 280SE 4.5: Baby Gustav
1991 300TE 4Matic: Gretel the Snow Bunny - sold
1978 300SD: Katz the Free Man - given away
1980 Redhead: Darling Wife