MB didn't have any 4 wheel ABS systems until 4-matic cars came to the US in 1990. NOW almost all of the traction systems need a 4-wheel system to operate.
The 1995 C280 didn't have 4 sensors unless the car was equipted with ASR.
With 3 sensors the ABS system is more stable for the average driver. However a 4 wheel system is better for a "real" driver!!

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator