2003 Mercedes-Benz SL-Class - No brakes

I wonder what sensors they use? Brake hydraulic fluid pressure? Pad position sensors? Pad-to-disk force sensors? Along with wheel rpm sensors of course. Fun to speculate.

I wouldn’t guess a brake sensor failure would lead to a no-brakes-at-all symptom. But I wouldn’t guess that a simple airspeed sensor failure could cause a commercial jetliner crash either.

George, meet Wiki:
Sensotronic Brake Control - Wikipedia

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That Wiki entry is well written.
Especially pertinent is the section titled “Problems”. To quote…

“ In May 2004, Mercedes recalled 680,000 vehicles equipped with the system; in March 2005 a total of 1.3 million vehicles were recalled. In 2006 high-volume models such as the E-class returned to conventional hydraulic brake systems. Low-volume luxury models such as the SL, the Maybach and the SLR continued to use SBC due to the prohibitive cost of redesign.

In a letter - only to US customers - dated August 2018 a warranty addendum was sent extending coverage for 25 years and unlimited miles on the following SBC components.

  • Hydraulic control unit
  • Hydraulic Pump
  • Pressure Reservoir
  • Brake Operating Unit
  • Front and Rear wheel speed sensors
  • Brake lamp switch
  • Yaw Rate Sensor

Out of warranty repairs of these items can be reimbursed by MB if proper documentation is provided.”

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