5 Series E60 M5 (S85) SAL
Advantage: Shortest possible stopping distances in emergency-braking situations, because the ABS control
threshold is reached at all four wheels.
In emergency-braking situations, drivers often fail to apply sufficient force to the brake pedal. ABS regulation is
then not activated.
In the following situations, the return pump increases the brake pressure until ABS regulation is activated:
-
When the brake pedal is rapidly depressed with insufficient pedal pressure
-
When the brake pedal is depressed slowly and the demand for deceleration is subsequently high, after one
wheel reaches the ABS control threshold.
Which wheel locks first depends on load and coefficient of friction of the road surface.
Example of a typical situation:
The traffic slows, making light braking necessary at first, but then demands as short a stopping distance as
possible.
Electronically controlled deceleration
The electronically controlled deceleration (ECD) reacts to a demand from the Active Cruise Control (ACC).
When ACC requires deceleration, DSC responds by applying the disc brakes on all four wheels (maximum rate
of deceleration 2.5 m/s
2
).
When the car is on a decent with the speed preset by the driver, ECD automatically applies the brakes in order
to keep the car's speed constant at the preset value.
When the brakes are applied automatically in this way, the brake lights are activated in accordance with the
requirements of road-safety legislation. The light module does not activate the brake lights unless the vehicle's
rate of deceleration is greater than 1m/s
2
. This prevents the brake lights from flickering on and off.
Trailer stabilising control (only in conjunction with trailer module for E60 and E61)
Trailer stabilising control detects when a trailer is rocking about its vertical axis. The system functions at a speed
of about 65 km/h when the trailer socket is in use.
With the aid of the DSC sensors, Dynamic Stability Control (DSC) monitors the vehicle's yaw behaviour. If the
trailer's rocking motion exceeds the limit, the engine output is reduced. In addition, DSC brakes all four wheels
automatically.
If DSC is deactivated or faulty, then the trailer stabilising control does not work either.
Tyre defect indicator
The Run Flat Indicator (RPA) is not a function of the Dynamic Stability Control system.
RPA is integrated into the DSC control unit as the four wheel speed signals are required for this function.
By comparing the speed signals for all four wheels, the system detects differences in rolling circumference at the
individual wheels. This enables the system to recognise a sudden loss of pressure in the tyres.
Operation
The DSC button is in the centre console switch cluster (SZM)
The DSC button has 2 functions that can be set by pressing the button for different lengths of time.
Press button
Function
Remarks
short
< 3 seconds
DTC function activated.
DTC indicator light on.
DSC indicator and warning light on.
long
> 3 seconds
DSC is completely deactivated
DSC indicator and warning light on.
SBT Dynamic Stability Control DSC 8 E60, E61, E63, E64
BMW AG - TIS
23.02.2013 19:56
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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