Drag torque reduction (MSR)
During deceleration and engine braking
conditions engine drag torque can cause
the rear wheels of a vehicle to lock on
low traction surfaces, especially in high
speed, low gear driving. This can lead to
loss of traction in the rear. When drive
wheel speed is slower than front wheel
speed the ECM will suspend vehicle
coasting by increasing throttle opening
angle and engine torque.
Dynamic brake control (DBC)
The DBC function provides increased
braking pressure, up to ABS threshold,
during emergency braking situations.
The DSC control unit will implement
DBC function when brake pressure
builds rapidly with application of the
brake pedal.
DBC triggering conditions:
Brake light switch on
Brake pressure in master cylinder
above ABS threshold
Brake pressure build up speed
above threshold
Vehicle road speed above 3 mph
Pressure sensor self test completed
and sensors OK
Vehicle travelling forward
Not all wheels in ABS regulation
range
Suspension, Steering and Brakes — General
http://ebahn.bentleypublishers.com/BMW/3/E46/Repair%20Manuals/3...
12 of 24
2/25/2009 10:24 PM
Summary of Contents for 1999-2005 M3
Page 1: ......