1 Series E87 118d (M47T2) 5-door
Brake disc drying on wet roads
Braking dry removes moisture that gathers on the brake discs during journeys on wet roads or in rain. The brake
pads are lightly applied. This function also shortens the brakes' response time.
Depending on the signal from the rain sensor and the position of the wiper switch, DSC cyclically generates a
low brake pressure. This creates no measurable deceleration on the vehicle. The brake pads are cyclically
applied. This means that the brake disc are regularly wiped down. How often and how long the brake pads are
applied depends on:
•
The intensity of the rain, e.g. the speed of the windscreen wiper
•
Road speed greater than 70 km/h
Fading compensation
Fading means: braking effect deteriorates as a result of high brake-disc temperatures.
If fading is detected, DSC reacts by increasing the brake pressure above that specified by the driver.
At very high brake-disc temperatures, fading compensation is indicated by the following:
•
General brake warning lamp lighting up yellow
•
Check-Control symbol in LCD display in instrument cluster lighting up yellow
DSC detects fading as follows: DSC compares the current vehicle deceleration with a nominal value based on
the current brake pressure. DSC increases brake pressure until the nominal deceleration is achieved or until all
wheels are subject to ABS control. The process is ended when the brake pedal is no longer depressed or when
the speed drops below a certain threshold.
Soft stop when braking to standstill (only E87 with 6-cylinder engine, E90, E91, E92, E93)
Soft stop prevents the vehicle from jolting to a stop (e.g. with an inexperienced driver).
When the vehicle is braked to a standstill, there is no uncomfortable jerk (causing the occupants to "lurch"
forward). DSC calculates the moment that standstill can be expected from the current road speed and
deceleration.
Just before standstill is achieved, the brake pressure on the rear axle is reduced so that the vehicle stops with
practically no jerking. Soft stop is only active for light braking, so that the shortest possible stopping distance can
still be achieved in emergency braking situations.
Start-off assistant
The start-off assistant prevents the vehicle from moving unexpectedly when the driver moves his foot from the
brake pedal to the accelerator pedal (e.g. when pulling away on a hill):
•
uphill in forward gear
•
uphill in reverse gear
It does this by maintaining the brake pressure needed to hold the vehicle.
The gradient is recorded by the longitudinal-acceleration sensor in the DSC control unit. From the gradient, the
necessary braking torque or engine torque is calculated. When pulling away is detected, brake pressure is
reduced as soon as the available engine torque is sufficient to move the vehicle in the direction required. The
start-off assistant is deactivated when the parking brake is applied. If no move is made to pull away within 2
seconds of the brake pedal being released, the start-off assistant will be deactivated.
Adapted interface for option 544 "Cruise control with brake function"
> E92 from 06/2006 and
> E90, E91 from 09/2006 (up to 09/2006: "cruise control with brake function" always with LDM) and
> E93 from 12/2006
SBT Dynamic Stability Control Mk60E5 E85, E86, E87, E90, E91, E92, E93
BMW AG - TIS
18.01.2013 18:31
Issue status (12/2007) Valid only until next DVD is issued
Copyright
Page - 7 -
