What is the use of DSC, ASC, ASC+T adn ETC

[Ah Yew]

Read thru alot of thread, found these DSC, ASC ASC+T and etc..... What is this actually stand for and what is the function. My E46 got ASC, but don'r know what is that and never try. Can anybody explain??

 

[astroboy]

Try this..

Click More on DSC vs ASC+T write up..

Exact quote from the link:

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 has been available on a variety of BMW models over the last three years. It is available on the new 3 Series sedan, the X5 and other 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.

More on ASC+T..

 

[loafer]

To cut the long story short, all these functions let you drive like a PRO racing driver on the track without worrying about crashing out!

 

[turbology]

What is the use of DSC, ASC, ASC+T, and etc

My Answer: For people who can't handle oversteer, understeer, powerslide, skidding, hydroplane, sliding and etc

To cut the long story short, all these functions let you drive like a PRO racing driver on the track without worrying about crashing out!

Errr... okay.

 

[loafer]

My Answer: For people who can't handle oversteer, understeer, powerslide, skidding, hydroplane, sliding and etc



Errr... okay.

Err, joke.

 

[Ah Yew]

Wow... very good lecture, but a bit technical... Anyway thank you Astroboy. :top:

For Loafer & Turbology, I think you got your point also. Sometime even you got very good driving skill, with this kind of technology, it will make you more perfet. At least that's what I think....:wink:

BTW, how you really know this thing is working or not working.

 

[astroboy]

Go to a big vacant parking lot with wet surface and drive hard to throw the car around, you will notice your engine power cut off no matter how u throttle and DSC indicator will lit on the dashboard telling u its working hard to keep the car within traction.. :wink:

.... now try it with the DSC off.... good luck!

 

[Ah Yew]

Ho Ho Ho.... I think I don dare to try this... Baru kahwin.....

 

[loafer]

Better now than when you have kids!

 

[turbology]

Ho Ho Ho.... I think I don dare to try this... Baru kahwin.....

You need to learn it.
Things can come handy when you need it most at panic situation.

Here is a start:
1. Raining day. Light rain or the road still wet. Not heavy rain until vision is less than 100m
2. Big parking lot. No car, no people, no pothole, no tree, FLAT surface
3. Safety belt on. Put on a motorbike helmet if you have any..

When 1, 2 & 3 applied: Drive your car in a circle. Start slowing from 20km, and climb slowly. Max at 60km. Now, try it with DSC off. You will notice a huge different.

 

[turbology]

on second thought, you can call me when 1,2 and 3 apply
You will be on passenger while I show you counter-wait-brake technic.

 

[davidtch]

Ho Ho Ho.... I think I don dare to try this... Baru kahwin.....

Juz sign up 4 BMW Advance Driving Training. U got 2 do tis not wif ur ka.:top:

 

[davidw]

Just sign up for BMW Driver Training and you will know what are they as davidtch said. When for the 1st driver training, it was really fun.

 

[astroboy]

DSC doesn't detect aquaplane?!

My front CSC2 is 32k km old and during a recent balik kampung journey, experienced heavy rain. Was driving with 120% alert and noticed my E90 320i suffer aquaplane on few occasions due to the wide 225mm semi bold tyres.. farnee thing is the DSC light never lit! Am I correct to say DSC does not help in the event of aquaplanning?! Anyone?!

The wide tyre is no fun in the wet compare to my other mini RWD MPV which is on 185mm tyres..

 

[dzuljazz2001]

Better now than when you have kids!

:top: thats a good one ...made me smile ...big smile ...hahahaha ....:top:

 

[dzuljazz2001]

My front CSC2 is 32k km old and during a recent balik kampung journey, experienced heavy rain. Was driving with 120% alert and noticed my E90 320i suffer aquaplane on few occasions due to the wide 225mm semi bold tyres.. farnee thing is the DSC light never lit! Am I correct to say DSC does not help in the event of aquaplanning?! Anyone?!

The wide tyre is no fun in the wet compare to my other mini RWD MPV which is on 185mm tyres..

:listen:120% is over alert .....:wink: ....not good to be 120% alert as it will make you very rigid and out of focus .....long distance driving needs just enough alertness and total body relaxation.

regarding the DSC not lighting up ...did you switch it on? I assume u did. either u hv a fuse bulb or a faulty wiring(very unlikely) ....or the activation was just too fast for your 120% alert eyes to detect ....just kidding boy ...:wink:

nb:if all 4 wheels are "n-sync" the DSC will not work, even in aqua-planning situation.
go above 120kmh (with water depth more than 5cm) and you will aqua-plane on any tyre type/size ....:wink:

 

[Ennui78]

Wah...all of you very naughty la. Ah Yew..... methink you should not meddle with the butang-butang and leave DSC or DTC on.

I've driven fast on the highway and at certain patches of uneveness due to either wetness or the poor condition of the tarmac, I've seen the DTC/DSC lights flash. You DO actually feel a cut in engine power. And some jerkiness due to the brakes applied 'unevenly' on the tyres that may potentially lose traction. The sensation is enough to remind me to slow down and drive a bit more like an auntie.

 

[astroboy]

...
nb:if all 4 wheels are "n-sync" the DSC will not work, even in aqua-planning situation.
go above 120kmh (with water depth more than 5cm) and you will aqua-plane on any tyre type/size ....:wink:

5cm?! No need 5cm la, any water level that's deep enough to submerge the water channel on your tyre surface is enough to provide your car the "lift"..

"..all 4 wheels are "n-sync" the DSC will not work.." .. that's what I thought. Aquaplane normally happen when the front wheels are lifted (on the straights). For RWD, the transaxle revolution on the rear wheel would be very unlikely to suffer aquaplane because the rear wheels are literally stepping on a "dry" track rolled over by the front wheel where water has been dispersed by the front wheel. As a result, even both front wheels are lifted during aquaplane, wheel revolution on all 4 wheels remain in sync, no steering change in direction despite the car is shooting an off tangent projectile caused by the aquaplane, DSC sensor won't notice this.

On the other hand, FWD car once front wheels are lifted during aquaplane, it will spin faster (if gas pedal remain depressed) and driver will notice a sudden raise in RPM like car suddenly engage neutral and loss drive while a RWD can continue to power the car.. another situation where RWD is far more superior .. :wink: but FWD DSC would detect the non sync in wheel revolution during aquaplane as oppose to RWD..

 

[Ah Yew]

Hai Ennui78,

You're right...it happen to me also when driven fast on the uneveness or the poor condition road....By the way...I give my car to my wife lo....me no car lo.....

Astrobuy,

Sorry for interrupt...What happen to you..it happen to me also...Big tyre no fun...especially non-directional tyre..

 

[dzuljazz2001]

5cm?! No need 5cm la, any water level that's deep enough to submerge the water channel on your tyre surface is enough to provide your car the "lift"..

.....still depends on the speed .... if its too slow, nothing will lift ... .hiihihiihihihi ..... if you know what I mean ... but on a serious note astroboy, well explained ... i cant agree with you more....some tyres at 80km will immediately aquaplane but with good wet weather tyres, at 100kmh will still provide adequate grip.:top::top:
kalau tyre botak, kena 5mm of water level pun da bole slide....:wink: