Specifications

34
Testing Testing ABS and Traction Control Systems
to the vehicle. When DBC is activated, the rear axle is controlled with Select-Low logic and the
front wheels are regulated individually. DBC continues until one of the following conditions occurs:
• The driver releases the brake pedal.
• Brake pressure falls below threshold.
• Vehicle road speed falls below 3 MPH.
• A fault occurs with any of the necessary input sensors.
A DBC fault will illuminate the yellow “BRAKE” (ABL) lamp to warn the driver. Depending on the
failure, the DSC lamp may be illuminated as well.
Maximum Brake Control (MBC) is designed to support driver-initiated braking by building up
pressure in the rear brake circuit when the front wheels are already in ABS regulation. The
additional braking pressure is designed to bring the rear wheels up to the ABS regulation point,
shortening the stopping distance. MBC is triggered when the brakes are applied more slowly than
the threshold needed for a DBC regulation. The triggering conditions are:
• Both front wheels in ABS regulation
• Vehicle road speed above 3 MPH (5 KPH)
• DBC and pressure sensor initialization test successful
• Vehicle moving in a forward direction
• Rear wheels not in ABS regulation
If the threshold for MBC triggering is achieved, the DSC III control unit will activate a pressure
buildup intervention by activating the return pump. The pressure at the rear wheels is increased
up to the ABS regulation point. This ensures that maximum brake force is applied to the vehicle.
The MBC function will be switched off if one of the following conditions occurs:
• The front wheels drop out of ABS regulation.
• The driver releases the brake pedal.
• Brake pressure falls below a specific threshold.
• Vehicle road speed falls below 3 MPH (5 KPH).
• A fault occurs with any of the necessary input sensors.
A MBC fault will illuminate the yellow “BRAKE” (ABL) lamp to warn the driver. Depending on the
failure, the DSC lamp may be illuminated as well.
Teves DSC III MK 60 Wheel Speed Sensors (Hall Effect)
For Teves DSC III MK 60 systems, active wheel speed sensors operate on the principle of the Hall
effect. The sensor element is a ferromagnetic alloy that changes its resistance based on the
influence of magnetic fields. The sensor element and evaluation module are two separate
components within the sensor housing. The active sensing of the magneto resistive sensor is
particularly suitable for advanced stability control applications in which sensing at zero or near
zero speed is required. A permanent magnet in the sensor produces a magnetic field with the
magnetic field stream at a right angle to the sensing element. The sensor element is affected by
the direction of the magnetic field, not the field strength. The field strength is not important as long
as it is above a certain level. This allows the sensor to tolerate variations in the field strength
caused by age, temperature, or mechanical tolerances.