7
DYNAMIC STABILITY CONTROL (DSC III)
All  of  the  familiar  braking  and  straight  line  traction  control  features  and  system  communi-
cation  carry  over  from  DSC  II.    Based  on  select  high/select  low  logic,  the  DSC  III  control
module  selects  a  vehicle  stabilizing  strategy  based  on  the  specific  input  signal  values  it  is
monitoring  at  the  moment.    For  all  DSC  strategies  this  begins  with  engine  intervention  to
reduce torque:
•For  the  750iL  this  is  handled  via  CAN  communication,  DSC  III  to  EML  to  minimize  the
throttle  angle  of  the  DK motors  (750iL).  For  the  740i/iL  and  540iA  this  is  handled  by
direct DSC III activation of the ADS II throttle housing.
• If additional torque reduction is necessary, DSC III informs DME over CAN to:
• Retard ignition timing
• Shut down the fuel injection to individual cylinders
DSC III monitors under/oversteer conditions through the following components:
• The driver’s desired steering angle - steering angle signal over CAN bus.
• Vehicle speed and speed differential at front wheels - wheel speed sensors
• Dynamic  forces  of  lateral  acceleration  and  yaw  placed  on  the  vehicle.  This  is  possible
with two new components which are discussed further on. The results are as follows: