SBC additional functions, function - GF42.46-P-2000T

MODEL 211.004/006/016/023/026/028/042/043/056/061/065/070/076/206/216/223/226/242/243/256/261/265/270/276/606/616 up to 31.5.04, 211.080/082/083/087/280/282/283 up to 30.11.04 

Function 

The SBC system features a series of functions to assist the driver or assist braking and therefore contribute to the safety of the vehicle.

Safety-relevant functions 

Precharging 

(overcoming play)

This function, which is always active, assists the braking readiness by immediately and briefly applying the brake pads (precharging) if the driver releases the accelerator pedal quickly.

This reduces the brake pressure buildup and shortens the stopping distance during normal operation.

Dry braking 

This safety function helps to ensure that the vehicle is ready to brake if the brake disks are wet by briefly dry braking them.

Wet conditions are recognized via the activation of the windshield wipers. The SBC control unit (A7/3n1) receives information on windshield wiper frequency via CAN.

This reduces the brake pressure buildup and shortens the stopping distance during normal operation.

Dry braking is carried out approximately every 7 to 14 minutes depending on the amount of precipitation until the driver applies the brakes.

Comfort-relevant functions 

SBC Hold 

This function prevents the vehicle rolling backwards on a slope or during long idle times at traffic lights and therefore provides start-off assistance.

Operation 

The SBC Hold function is activated by "overbraking". That is to say, when the vehicle is stationary and the driver's foot is on the brake pedal, the driver briefly depresses the brake pedal with slightly more force.

The successful activation is permanently displayed by "SBC H" in the multifunction display (A1p13) in the instrument cluster (A1). This increases the driving comfort since the driver may now remove his foot from the brake pedal.

The holding function is deactivated:

• When the driver presses the accelerator pedal and the vehicle starts to move.
• When the selector lever of the automatic transmission is moved into position "P".
• And by pressing the brake pedal again with the specified brake pressure until the display "SBC H" goes out.

A warning message "Brake immediately" appears in the multifunction display (A1p13) of the instrument cluster (A1) when SBC hold is active and when a door is open and simultaneously a driver's seat belt lock is open or defective and when there is a system failure.

Function 

A7/3n1 If the set delay calculated by the SBC control unit using the brake pedal travel exceeds a specified threshold during "over-braking", a fixed brake pressure is set. When the vehicle begins to move, the pressure is reduced in stages according to comfort levels depending on the road gradient.

SBC stop 

When this function is active, the vehicle decelerates by braking at a constant rate when the driver releases the accelerator pedal until the vehicle comes to a complete stop. Since the brake pressure is maintained until the vehicle comes to a complete stop, the driver is not required to keep the vehicle stationary by pressing the brake pedal. The braking procedure is interrupted automatically if the driver presses the accelerator pedal, e.g. to start the vehicle moving again or to accelerate.

The driver is relieved of a task since he is only required to press the accelerator pedal when driving in a traffic jam and is not required to keep the vehicle stationary by pressing the brake pedal.

Operation 

At a speed of < 15 km/h the SBC stop function is activated with the cruise control selector lever through one of the following 3 actions:

• Pulling towards the driver ("Resume")
• Pressing up ("Set and accelerate")
• Pressing down ("Set and decelerate")

The activation is displayed permanently by "SBC S" in the multifunction display (A1p13)

The stop function is deactivated:

• by pressing away the cruise control selector lever.
• when reverse gear is engaged and then starting off.
• when the selector lever of the automatic transmission is moved into position "P".

Upon completion the display in the instrument cluster (A1) goes out. A warning message "Brake immediately" appears in the multifunction display (A1p13) of the instrument cluster (A1) when SBC hold is active and when a door is open and simultaneously a driver's seat belt lock is open or defective and when there is a system failure. The cruise control, DTR, and limiter functions remain unaffected. The SBC Stop function must be switched off beforehand, however.

Softstop 

Below 6 km/h by briefly reducing the brake pressure softstop reduces the jolt which occurs when braking immediately upon reaching a standstill

This function is deactivated during emergency and full braking in order to optimize the stopping distance."

SBC normal braking, function	GF42.46-P-1000T
SBC function brake application in the event of system fault	GF42.46-P-3000T
SBC control unit, location/task/function	GF42.46-P-4500SL