Turning on/off the DSC

[BMV23]

One more thing, DSC and ASC are not the same thing. ASC is used for straight line traction, cutting throttle to avoid wheel spin. DSC is a combination of ABS and ASC for cornering stability using the brakes and throttle.

Wow, you must've just chose to not read ANYTHING from this thread before you posted this huh? You actually THINK that they had ASC, and decided to improve on it with the only difference of adding anti-lock braking, and thus creating DSC??? Plus your whole statement that DSC and ASC are not the same things, and then proceeding to state that ASC is one of the factors of DSC contradicts itself. Essentially you’re just saying DSC is abs! Hahahaha- Okokok, so basically let me get your story straight: once upon a time they had asc, but not abs (although abs has been around for the last couple decades) and then they decided to start adding abs to the system, and THAT is your definition of DSC- and now with the addition of anti lock brakes, it allows for greater stability and handling??? Yea buddy, sure.... Make sure you don't turn off your abs when you hit that DSC button then. Hahaha-

 

[ariper79]

Okay smart guy. First off ASC is Anti-Slip Control, used for straigh line acceleration, which is why there is a ACS throttle motor on some vehicles to cut the engine torque output to stop the wheels from spinning off the line. ASC, which was the sytem used befor DSC was around, had no effect on the non-drive wheels. It would use ABS to pulse the drive wheels in order to get the vehicle moving in snowy or icy conditions. DSC came along and is BASICALLY a combination of ASC and ABS. DSC, the new and improved slip control system, uses ABS on ALL wheels to correct for oversteer and understeer. It still uses ASC, or Anti-Slip Control, to cut engine torque output in extreme situations. Sorry you didn't understand and decided to post a arrogant post like that, really make you look kinda stupid!

 

[ariper79]

Undiean,
That last post wasn't directed at you, just wanted to get that out of the way.

I realize what your saying, and understand what the website says. I am just explaining it in a different way. There is only one ABS hydraulic pump on the vehicle, and only one ASC throttle motor. DSC uses the ABS pump to pulse the brakes on individual wheels, and ASC to cut the throttle when needed. Yes they are not the exact same thing, but DSC uses both of them to control the vehicle. We on the same page?

 

[undien717]

Undiean,
That last post wasn't directed at you, just wanted to get that out of the way.

I realize what your saying, and understand what the website says. I am just explaining it in a different way. There is only one ABS hydraulic pump on the vehicle, and only one ASC throttle motor. DSC uses the ABS pump to pulse the brakes on individual wheels, and ASC to cut the throttle when needed. Yes they are not the exact same thing, but DSC uses both of them to control the vehicle. We on the same page?

As I quoted from www.bmw.com in my previous post, ASC is really just a sub function of DSC, applying brakes to individual spinning wheels until grip is achieved. It might be possible that DSC uses the ABS system to apply brake pressure, but I've never read this before. Please show me a source from your info. The acronym of ASC you've mentioned is also incorrect based on the info I've searched for in www.bmw.com (on previous post).

ASC, which was the sytem used befor DSC was around, had no effect on the non-drive wheels. It would use ABS to pulse the drive wheels in order to get the vehicle moving in snowy or icy conditions.

I don't see how the system to avoid brake lock up can help you power out of the snow. In snowy conditions, the 2004 owner's manual suggests that you turn off DSC in order to turn on DTC (I've also explained this on my previous post) so you can power through the snow.

 

[BMV23]

Like I posted a long long time ago, when the RED brake light is on it means there is a problem. It could mean that your brake fluid is low, which will turn off all stability control, including ABS. You cannot do this manually, this only happens when there is a problem. The reason for deactivating the abs in such a situation is as follows. If the fluid was low, possibly because of a leak, and the ABS started to kick in, there is a danger of spinning out. If there is not enough fluid to pulsate all brake circuits, one or two of the brakes may fail to pulsate, making you spin and DIE!

okokok, the reason why i was confused with wat you were saying was first of all, you didn't really elaborate on what you were saying originially nor with your following post. You said here that you can turn off ABS making it seem like ABS was the same as DSC, however ABS cannot be turned off at all. Only Dynamic Braking Control, which is somethign separate, can be turned off. Second of all, ASC isn't just used for straight line traction, it is used in cornering, or basically whenever you lose grip. this can be seen in the example of ASC at bmw.com. Second, it states that DSC is the system responsible for engine management when the car loses grip, and ASC is the system responsible for applying brakes to the individual wheels. So I dunno where youre getting your source that ASC isn't able to apply brakes to inidividual wheels and that DSC just controls the brakes. Secondly in your new post u said "It would use ABS to pulse the drive wheels in order to get the vehicle moving in snowy or icy conditions. " but this is ALSO wrong because you turn OFF ASC to get out of snowy conditions. Why the hell would u want the brakes to be applies when climbing out of ice??? that's pretty stupid.

also you didn't seem to read the past posts where is said that the red light can indicate that your e-brake is left up. So when you said there is no way to do this manually, it made it evident that you make posts without reading those who posted before you. smart buddy

 

[ariper79]

I never said that you can turn off the ABS manually, I said it happens when there is a problem such as low brake fluid. This is indicated by the red brake light being on. If you want to try it, drain your brake fluid until the light comes on and slam on your brakes at about 30 or so, you don't have ABS, (I AM NOT SUGGESTING ANYBODY TRY THIS, JUST TRYING TO PROVE A POINT). I got all of my info from the BMW training manuals that I got while attending STEP, a BMW technician training course. It's hard to explain how the whole system works just by typing back an forth like this, let me try again. ASC is used to stop the drive wheels from losing grip, yes, this is a function of DSC, now. ASC was used a long time ago, when DSC did not exist. ASC does apply the brakes when trying to get traction in the snow, if it did not pulse the brakes, your wheels would spin like crazy and you would go no where. DSC is the name given to the stabilty control system. This includes ABS, ASC, DBC...and so on. The ABS pump is what modulates the fluid pressure to the brakes, pulsing them on and off quickly. The Dynamic Stability Control system uses this pump to apply single brakes when needed. I did forget about the e-brake being left up causing the red light to come on, my fault. Let's not get all crazy, talk about this like rational people. Smart guy

 

[BMV23]

I never said that you can turn off the ABS manually, I said it happens when there is a problem such as low brake fluid. This is indicated by the red brake light being on. If you want to try it, drain your brake fluid until the light comes on and slam on your brakes at about 30 or so, you don't have ABS, (I AM NOT SUGGESTING ANYBODY TRY THIS, JUST TRYING TO PROVE A POINT). I got all of my info from the BMW training manuals that I got while attending STEP, a BMW technician training course. It's hard to explain how the whole system works just by typing back an forth like this, let me try again. ASC is used to stop the drive wheels from losing grip, yes, this is a function of DSC, now. ASC was used a long time ago, when DSC did not exist. ASC does apply the brakes when trying to get traction in the snow, if it did not pulse the brakes, your wheels would spin like crazy and you would go no where. DSC is the name given to the stabilty control system. This includes ABS, ASC, DBC...and so on. The ABS pump is what modulates the fluid pressure to the brakes, pulsing them on and off quickly. The Dynamic Stability Control system uses this pump to apply single brakes when needed. I did forget about the e-brake being left up causing the red light to come on, my fault. Let's not get all crazy, talk about this like rational people. Smart guy

just like undien said above....i would think that you would have to turn OFF the asc in order to get ouf of the snow, or else the car would just interpret it as lost traction when the wheels spin, and thus apply the brakes. And DSC is a system which includes DBC, ASC, and applying the functions of ABS in the system, but turning off DSC doesn't affect the normal functions of ABS. I thought you were saying otherwise, but i guess i misunderstood wat you were meaning to say. It sounded like you were saying that ABS was one of the sub funtions of DSC, whereas it is more simply a means that the DSC system uses in order to regain stability. I thinkyou said it a lot more clearer here tho cuz before when you said "the reason for deactivating the abs..." it made it seem like the driver manually did this. I didn't realize you meant "the reason the abs is deactivated in these conditions is..." so basically it was a misinterpretation of your words. Also i wasn't aware you were talking about the old system of ASC rather than how it is used now. Regarding your previous post, I still never came across any info about ASC cutting the torque and acutally having control over the engine, it seemed more like that was new feautre for the DSC in the way it is described at BMW.com. ASC seemed like it was more about applying the designated brakes.

 

[Wadula]

ASC really controls the engine to a certain extend. in the first stages the engine power is being reduced. you can feel that when redlinig in first, getting in second and letting the clutch fly. if it is wet outside you stay on the gaz completly but the engine looses revs. the system reduces power output.

 

[TSilver330CI]

Ok I thought I had this figured out, but as I keep reading your replies to this thread, I am getting more and more confused.

I own a 2001 330 CI. I am assuming that DSC and DTC are on all the time, unless I push the DSC button, which puts that yellow icon light on my dashboard, indicating that DSC is off, but DTC is still on. If I supposidely hold down the DSC button, both DSC and DTC are now off as indicated by an amber light?

The thing is when I hold down the DSC button, I never get an amber light, just nothing happens.

If DSC and DTC are both some kind of traction control.... what are the pros and cons to both? Which is better in this crappy jersey snow that I am constantly facing.

THANKS!

 

[ariper79]

ASC helps get traction in snow by pulsing the brakes to control wheel spin, and yes it can be a bit intrusive. That is why BMW suggests to turn on DTC in snowy or ice conditions, it allows for slightly more wheel spin, but it still pulses the brakes if wheel spin is too great.

I know I was explaining all this differently than the website, sorry If i'm throwing anybody off. I believe we are both trying to explain the exact thing, just in different ways.

The whold ABS thing, that's completely my fault. DSC uses the ABS pump to control individual wheels when needed. I didn't mean to say that the DSC puts on a full on ABS stop if it detects understeer or oversteer.


Try not to think of ASC, ABS, DTC, and DSC as different systems, DSC is what's it's called now. Basically, DSC is a combination of all those things now, using them when needed. I don't know if that helps or hurts your thinking, but I'm trying.

 

[nate_ids]

My light stays on which tells me the system has malfunction. How do you reset the DSC system. Pushing the DSC buttom does nothing. I've had a computer check for error codes in the system and nothing shows. Can it be a bad wheel sensor or the DSC control box? Any advise would be appreciated.

 

[nate_ids]

That's not right. ABS is always on- you can't turn that off. DSC and ASC are the exact same thing, the system is just called Automatic Stability Control instead of Dynamic Stability Control in older models. When you press the DSC button, a yellow exclamation light remains lit, which means that DSC has been deactivated, taking away the engine’s ability to control the amount of torque to the wheels when the car senses that there is wheel spin. When DSC is activated, it will decrease the torque to the wheels in order to stabilize the car. Another function of DSC is to detect whether one wheel is spinning and the other wheel isn't. The DSC system will then apply the brakes to the wheel that is spinning until the tire has achieved grip. When DSC is active, nothing will be lit, but when DSC is actively being used (i.e. when you're taking a very tight corner), the exclamation light will flicker, serving as an indicator that the DSC is actively stabilizing your car and warning you that your are driving on the edge of stabilization.

As I've mentioned before, when you've pressed the DSC button, the yellow exclamation light will remain lit (not flashing), indication that DSC has been deactivated and that DTC (Dynamic Traction Control) has been activated. DTC provides rear wheel vehicles with greater propulsion. In the 3 Series and Z4 Roadster, DTC also plays a role when on bends - it enhances the car’s propulsion and its sports-style qualities. The driver is in full control of their vehicle within a predetermined parameter: the regulatory functions are inactive (taken from www.BMW.com). When you have pressed the DSC button again to reactive DSC, DTC will become deactivated.

When you hold down the DSC button for 3 seconds, the yellow exclamation light will turn on as well as an amber "BRAKE" light. The lit amber BRAKE light indicates that you have turned off the DTC and DBC (Dynamic Braking Control). Since the yellow exclamation light is lit as well, the DSC has also been deactivated. There is no indicating light telling you that the DTC or DBC are actively stabilizing your vehicle. The function of DBC (Dynamic Braking Control) is to sense when emergency braking is taking place (when you slam on the brakes) and it applies the maximum braking power possible to the wheels.

Turning off the DSC and activating DTC is useful when your BMV needs to power out of a ditch or is stuck in the snow. It is also useful in the track since it gives rear wheel drive cars greater propulsion. Holding down the DSC button for 3 seconds will deactivate DSC, DTC, and DBC.

NOTE: In the xi series, the brake mechanism is called ADB-X (Automatic Differential Braking). This system is essentially the same as DTC, but the braking system is now applied to all four wheels.

*All this info was taken from the 2004 3 series owner's manual and from www.BMW.com

Thanks for the lengthy explaination. What you did not mention was if the DSC indicator lamp stays on even after you have pushed the DSC button. How do you reset the system? When the indicator lamp is on, it tells the driver the DSC system is off (I understand) but if it stays on then you have a system malfunction which could be the DSC controller or a wheel sensor or possibly something else. Can you tell me how to trouble shoot the system to fix this problem? Is it the button/switch? Would a faulty drive line or transmission mounts or engine mount cause the system to malfunction? Please advise....