Found this, I want some snow now.

Press and hold the DSC button for 10 seconds until the light goes out on the dash. This mode gives you active handling via the brackes but NO throttle managerment when DSC engages. It is also good for snow/ice operation when you want the tires to spin 

When do you want the tyres to spin Dan?

Dynamic Stability Control (DSC) is a suspension control system which goes beyond the single components of Anti-lock Brake System (ABS), Cornering Brake Control (CBC) and Automatic Stability Control + Traction (ASC + T).

The steering wheel movement, vehicle speed, transverse acceleration and yaw are all used by DSC to register imminent instability when cornering. DSC then intervenes via the engine management system, reducing drive torque and activating wheel brakes when necessary to keep the vehicle stable. These events occur within milliseconds.

DSC is, in fact, a further development of the ABS and ASC+T slip control systems.

While ASC + T analyzes the longitudinal forces occurring in straight-ahead operation, DSC additionally registers and analyses lateral dynamic forces.
When cornering at high speeds, DSC counters unstable vehicle states such as oversteering (rear of car brakes into a slide towards the outside of the curve) or understeering (front of car pushes towards the outside of the curve).
The DSC feature can provide maximum stability when cornering.
With DSC there is a significant reduction in the risk of skidding.
BMW's Dynamic Stability Control system is available on a variety of BMW based models.

Here's how it works:
DSC constantly compares vehicle speed, wheel speed, steering angle, and yaw rate with a benchmark of plausible and optimum driving conditions' data. In a fraction of a second, DSC recognizes a threatening instability and a danger of skidding. The DSC system can correct an unstable driving condition by applying precise braking action to the individual wheels. As with ASC, DSC will if necessary also cut back the engine speed to automatically stabilize the vehicle.

The ASC + T system will reduce engine output until the vehicle can move or or until acceleration can occur without the wheels spinning. If this reduction is insufficient, each drive wheel is braked individually until both wheels have optimum traction.

This makes it possible to drive on snow, wet roads or other slippery grounds without the wheels spinning. Even if the back wheels suddenly lose traction in a bend during acceleration, ASC + T intervenes so quickly that the vehicle is stabilized before it can oversteer and swing out of the bend. The instrument console informs the driver of any control intervention and the relevant situation.

The DSC computer constantly calculates an ideal driving condition that is compared with the current status. If the vehicle oversteers or understeers, the calculated ideal deviates from the measured status, and DSC will intervene within a few milliseconds via the engine management system by reducing the engine torque and applying the brakes on individual wheels where necessary.

DSC makes use of the ABS wheel-speed sensors and the following additional components:

steering angle sensor to detect the driver's chosen path.
lateral-acceleration sensor to define the lateral forces which must be transmitted to the road by the tires.
rate-of-turn sensor to define the vehicle's degree of rotary movement.
brake-pressure sensor to define the longitudinal forces acting between tires and road surface under braking.

Oversteer and Understeer:

In the case of oversteer, DSC brakes the outer rear (and, if needed, the outer front) wheel in order to correct the vehicle's stance by generating a counter-momentum to neutralize the oversteer. The braking effect is applied at both outer wheels.
In the case of understeer, DSC acts upon the inner rear (and, if needed, the inner front) wheel to regain vehicle stability. The braking effect is applied at both inner wheels.
The DSC's electronic and hydraulic systems are rapid and precise and they are hardly felt by the driver.

The above is thanks to BMWworld

Gazellio wrote:

When do you want the tyres to spin Dan?

When on a snowy hill, sometimes you need to have the control of the throttle rather than let the DSC take control. Especially if you need to turn the steering wheel whilst applying throttle to find grip....

I tried this a couple of times on an icy hill, impossible to get up with DSC unless you had a run up, where as with DSC off it was fine. Same applies on a wet grassy slope, the last thing you want as you're about to crest the hill is DSC intervention telling you you cant have any engine power! Again, been there done that, slid sidways down the hill  

dan_uk_1984 wrote:

Gazellio wrote:

When do you want the tyres to spin Dan?

When on a snowy hill, sometimes you need to have the control of the throttle rather than let the DSC take control. Especially if you need to turn the steering wheel whilst applying throttle to find grip....

I tried this a couple of times on an icy hill, impossible to get up with DSC unless you had a run up, where as with DSC off it was fine. Same applies on a wet grassy slope, the last thing you want as you're about to crest the hill is DSC intervention telling you you cant have any engine power! Again, been there done that, slid sidways down the hill

You don't necessarily want to floor it up the hill, but your foot can be more delicate than the DSC. For example if on a steep hill your front wheels will be light and will want to spin if the surface is slippery. DSC will then cut all power, even though your rear wheels have all the weight on and can push you up the hill no problem.

D 

like this then: http://www.youtube.com/watch?v=WycNOq9J1U4&NR=1

That hill was fun, absolute sheet ice. The HDC had to work really hard. There was a Nissan Patrol and a Jeep that had got half way up and they just left them in the ditch and walked home.

A Disco1 with mud tyres and lockers couldnt get up along with a diesel Defender (then he went down the hill forwards in reverse gear because he thought thats what he should do!!) 

dan_uk_1984 wrote:

That hill was fun, absolute sheet ice. The HDC had to work really hard. There was a Nissan Patrol and a Jeep that had got half way up and they just left them in the ditch and walked home.

A Disco1 with mud tyres and lockers couldnt get up along with a diesel Defender (then he went down the hill forwards in reverse gear because he thought thats what he should do!!)

Can't believe how fast & far you keep slipping back down the hill - just as well there was nobody behind you

Could have done it easier than the hash that guy was making of it! He didn't know what a "Low Range" was. Just like the Freelander that nearly crashed into me sliding sideways down the hill because he didn't know what the yellow button (HDC) was for.

It amazes me how people know nothing about their cars, bought a Disco2 where the owner referred to HDC as Hill ASCENT Mode! And said he couldn't tell the difference for going up hills!! 

Gazellio wrote:

Can't believe how fast & far you keep slipping back down the hill - just as well there was nobody behind you

As much as HDC will slow the car down it doesnt let you stop and as soon as I touched the brakes the ABS cut in and wouldnt stop at all. I'm not kidding when I say sheet ice! 

Check this out: http://www.youtube.com/watch?v=zMl7kCVtZ1M&NR=1

Mud underneith to bite into. Cheating! 

all above very interesting BUT ive been told by a landrover experience instructor that the dsc button shouldnt have been fitted to production vehicles as you shouldnt have the option to turn off as the button is not needed as the electronics do all the work onto no6 Range Rover

Everyone needs a hobby