ASC Sub-Functions: Oversteer

Oversteer occurs when the driver wishes to turn a corner and the tail of the vehicle slides outward leading the turn. This is caused by the rear tires loosing traction and not being able to hold against the centrifugal force acting upon the vehicle.

The MK60 DSC III can identify the situation and initiate a corrective action based on engine torque reduction followed by a controlled brake intervention sequence if needed.

Engine torque reduction is carried out by the DME from a request by the DSC via the CAN bus. The DME sends the torque reduction confirmation back to the DSC.

Fig 1: Oversteer Correction With MK60 DSC III

Courtesy of BMW OF NORTH AMERICA, INC.

Brake intervention is carried out by the MK60 hydraulic unit if the driver is not actively braking. An example of a brake intervention at the left outside wheel is as follows:

• All Inlet Valves are closed except for the left rear inlet.
• Intake Valve for rear circuit is opened.
• Both Changeover Valves are closed.
• Return pump operated.
  Fig 2: DSC Hydraulic Unit Hydraulic Diagram (Oversteer Correction)

  Courtesy of BMW OF NORTH AMERICA, INC.