Wheel Speed Sensors
The wheel speed sensors used are the same as on previous E38 and E39 models. The sensor is a hall effect type which sends a digital square wave to the DSC control unit. Unique to this sensor is the two wire versus three wire configuration as on most hall effect circuits.
The two wire hall effect wheel speed sensors receive a stabilized 8 volt power supply from the control module through one wire. The ground path for the sensor is through the second wire back to the control module.
The signal is generated by a pulse wheel affecting the voltage flow through the hall element in the sensor. The pulse wheel is integrated into the wheel bearing assembly, behind the seal. This protects the trigger wheel from foreign substances which may affect the wheel speed signal.
This creates a square wave signal with a low of .75 volts and a high of 2.5 volts.