Integrated Rotation Rate and Transverse Acceleration Sensor

The E46/16 uses the combined rotation rate/transverse acceleration sensor used in all Bosch DSC III 5.7 systems. The sensor is located under the drivers seat in front of the left seat rail and is attached to a plate with a rubber mounting to isolate it from vibrations.

For rotational speed, the sensor produces a reference signal of 2.5 volts and a voltage input signal from 0.7 to 4.3 volts. This signal represents the rotational movement (yaw) of the vehicle from the neutral straight ahead position.

Fig 1: Locating Integrated Rotation Rate And Transverse Acceleration Sensor

Courtesy of BMW OF NORTH AMERICA, INC.

The sensor also integrates the transverse acceleration signal (side-ways acceleration). The signal range is 0.5V increasing to 4.5V as side forces (g-force) increase. This signal is combined with the rotation signal to determine when to start DSC regulation.

Fig 2: Rotation Rate And Acceleration Sensor Circuit Diagram (DSC III 5.7)

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Adjustment of sensors is conducted separately in Service Functions of the Diagnosis Program even though both sensors are contained in one housing.