GF42.45-P-5134FA | Wheel rpm sensor, component description | 22.2.08 |
MODEL 203.7 as of model year 09/YoM 08 model refinement package
P42.45-2650-05
L6/1 Left front rpm sensor
L6/2 Right front rpm sensor
L6/3 Left rear rpm sensor
L6/4 right rear rpm sensor
Location
The rpm sensors are located on the respective steering knuckle.
Task
Standstill, direction of rotation and rpm of the wheels are recorded via the rpm sensors.
They are read in directly by the ESP and BAS (N47-5) control unit.
Function
The rpm sensor is a magnetoresistive sensor element (active wheel rpm sensor) and changes its resistance depending on the magnetic field applied to it externally (multipole ring on wheel).
The ESP and BAS control unit measures the current it supplies to the rpm sensor. Depending on the position of the multipole ring (negative pole or positive pole), a current strength of I =7 mA or
I = 14 mA is measured, producing a square wave signal.
The ESP and BAS control unit derives the wheel speed from this square wave signal.