Dynamic Stability Control-How Do You Know If It's Working?

[bmwcoupedriver]

I recently drove my 2003 330ci from NY to California.
On a VERY lonely stretch of mountain road in Wyoming my CD player quit.
Talk about lonely!
(Also no Radio or cell phone signal)
In any case, this is my question:
The manual says that the DSC is functioning as long as the light is OFF.
I used to see it blink occasionally (as it should) when I would go over some rough road or railroad tracks.
It's now been weeks since I have seen this happen, and I am now living in San Francisco. (Bringing it in to BMW San Francisco on Tuesday for the CD player)
Am I just being paranoid?

Joseph

 

[MrElussive]

The traction control, by default, is always on. When you push the DSC button (or hold it down) and the little warning light illuminates in the gauges, that means it's off. When the traction control is working (let's say you gassed it too hard on a wet road, starting from a stop and the rear wheels are starting to slip), the light will be blinking, indicating that it's doing its thing.
I think you have nothing to worry about because if there is a problem with the traction control system, you will get some kind of warning (usually the DSC warning light will just be on while driving, without you pushing/touching anything). If you want to be sure, just take the car out on a rainy day and floor it from a stop or basically just do something to get the DSC working but I'm sure it's fine since (as I said before) the system will let you know if there is a malfunction of any kind.

 

[///M SPEED]

MrElussive has it exactly correct. The DSC defaults as always on. If the light on the dash is continually on the DSC is off. When DSC is working the light will flash on/off anytime the system detects wheel slippage. It works very well.....

 

[bmwrocks]

I test the DSC just for fun sometimes by flooring it and trying to do a doughnut in a rain slick cul-de-sac or parking lot. The car will not spin the wheels or fish tail whatsoever. Try that. Just make sure you don't have an open drink in the car or any loose things laying around.

I also occasionally do an ABS test on a wet road. I read in Roundel that it is a good idea to flex all the emergency systems (with the exception of the airbags, seat belt tensioners, battery disconnect and door hook) every once in a while to keep them working properly.

 

[MrElussive]

That's kind of dumb advice from Roundel. If some function of the car isn't working properly (ABS, traction control, etc.), the car will let you know. Why do they want you practicing panic stops and burn-outs on public roads?

 

[Kirby]

I think Roundel has given good advice. The failure detection systems can't detect what I'll call "pending failures". An example is the antilock brake valve. When ABS is activated, the valve blocks or bypasses pressure to the wheel cylinder to prevent lockup. If this valve were to get dirty, etc. the it could test normal and pass diagnostics, but fail when it is activated under stress.

If you did needed ABS in an emergency, it would be a little late for the light to come on and say "ABS Failure" when you are 3 feet from plowing into another car.

Besides verifying the systems' functionality, the test performs another purpose - Driver training. It is good to know and feel how ABS, DSC, etc feels in a non-critical situation so it doesn't surprise you when it kicks in during real on the road situations.

 

[MrElussive]

Real men don't need ABS.

 

[Dave8812]

I concur^^^^

 

[Kirby]

Real men don't need ABS.

I guess that makes me a real man! So now you hit my hot button - shitty ABS systems. My '95 Suburban had antilock brakes but I disabled them! To make a long story short, the damn thing *never* worked right, then a wheel sensor failed and in the process also took out the ABS computer, making it work sporadically.

GM wanted $250 for a new wheel sensor and $1200 for the ABS computer. For a system that has been recalled, not fixed and the subject of lawsuits (GM & OEM Kelsey-Hayes) because of ongoing probems!

I pulled the fuse for the ABS computer. The ABS failure light was still on so I opened up the dashboard and pulled the light bulb - that way it won't raise a flag at inspection. No more ABS and the brakes work MUCH better now.

If you want some interesting reading about ABS failures, from USA Today - 1997:

http://www.usd.edu/~rlau/antilock.htm

"More recently, GM has been hit with allegations of ABS defects on 3.6 million 1991-95 Chevrolet, GMC and Oldsmobile trucks. NHTSA has 15,566 complaints about those brakes, and reports of 3,545 accidents and 703 injuries linked to the trucks' ABS. "

 

[epj3]

I guess that makes me a real man! So now you hit my hot button - shitty ABS systems. My '95 Suburban had antilock brakes but I disabled them! To make a long story short, the damn thing *never* worked right, then a wheel sensor failed and in the process also took out the ABS computer, making it work sporadically.

GM wanted $250 for a new wheel sensor and $1200 for the ABS computer. For a system that has been recalled, not fixed and the subject of lawsuits (GM & OEM Kelsey-Hayes) because of ongoing probems!

I pulled the fuse for the ABS computer. The ABS failure light was still on so I opened up the dashboard and pulled the light bulb - that way it won't raise a flag at inspection. No more ABS and the brakes work MUCH better now.

If you want some interesting reading about ABS failures, from USA Today - 1997:

http://www.usd.edu/~rlau/antilock.htm

"More recently, GM has been hit with allegations of ABS defects on 3.6 million 1991-95 Chevrolet, GMC and Oldsmobile trucks. NHTSA has 15,566 complaints about those brakes, and reports of 3,545 accidents and 703 injuries linked to the trucks' ABS. "

Kirby I am not kidding you - we had a 1995 chevy blazer we bought brand new from sauder chevy in New Holland PA. That thing was DEFINITELY a lemon.

You know what the biggest problem was? ABS!! First off, it was COMPLETELY worthless, ESPECIALLY on snow (It would lock the wheels up completely, then let go completely, then lock the wheels up again completely as it did its cycle - so you'd be put in a spin.)

Sauder GM - honest to god - replaced the ENTIRE ABS system 4 times before we got one that lasted until we traded it in for another GM (My dad is an engineer, a graduate from lehigh... and he was stupid enough to buy another gm!!!)

The really SAD thing is the ABS on my car, an 1988 325is (production 10/87), is 100 times better than the ABS on both our 99 pontaic montana AND my dad's 99 grand prix GTP!!!! VERY SAD!!! This is why I am not impressed with a SINGLE thing Gm does anymore. They are so far behind in technology that is is really kind of sad.

 

[epj3]

I recently drove my 2003 330ci from NY to California.
On a VERY lonely stretch of mountain road in Wyoming my CD player quit.
Talk about lonely!
(Also no Radio or cell phone signal)
In any case, this is my question:
The manual says that the DSC is functioning as long as the light is OFF.
I used to see it blink occasionally (as it should) when I would go over some rough road or railroad tracks.
It's now been weeks since I have seen this happen, and I am now living in San Francisco. (Bringing it in to BMW San Francisco on Tuesday for the CD player)
Am I just being paranoid?

Joseph

As someone else has said - it probably works when the light blinks.

Want to know the real way to tell that there IS a traction control system there to save your butt? Drive an older E30 in the rain!!! Then compare it to your car.

 

[Audible]

It kicked in on me the other day. I took off hard from a stop sign and when I grabbed 2nd gear and the tires broke loose the DSC shut me down within a second... It works, even when you don't want it to.

 

[selavia]

I dunno about abs making me less of a man; they actually saved my life once....

doing 100+ in my old camry, some idiot pulls out in front of me doing 50; I would have smashed his ass into oblivion or locked the wheels on 83 if it wasn't for abs. Maybe that makes me less of a man, but hell, at least I'm alive.

I have heard horrible things about chevy suvs/trucks have bad abs though.

 

[///M SPEED]

It kicked in on me the other day. I took off hard from a stop sign and when I grabbed 2nd gear and the tires broke loose the DSC shut me down within a second... It works, even when you don't want it to.

Hehe yea, usually when you don't want it too.

 

[bmwrocks]

Why do they want you practicing panic stops and burn-outs on public roads?

I do my testing in abandoned parking lots and cul-de-sacs full of young children playing.

You are kidding about the "real men don't need ABS" thing, right?

BMW ABS is not GM SUV ABS, so don't give up your BMW safety features just because your GM ABS was built by the lowest bidder.

 

[MrElussive]

Yeah, I was just being sarcastic about the ABS comment, I love ABS and it has saved my ass on more than one occasion.

The way I know my ABS is working is this: when I wash my car, I clean the wheels/tires with the EagleOne A2Z All Wheel & Tire Cleaner. Well once I'm done with the car wash, some rust-looking brown residue crap forms all over the rotors and when I am pulling out of the garage and first use my brakes, I feel the ABS working. I guess this residue crap on my brakes is slippery and the ABS thinks I'm slipping or something so it kicks in, but after the first or second brake (at VERY slow speeds), the residue stuff wears off and no more ABS.

It's funny we brought up this topic because I have an interesting story to tell about my traction control. When I got into my accident mad long ago when I first got the car, I'm pretty sure I shitted up the traction control (I don't wanna get into it). After the accident, my traction control wasn't kicking in when the rear wheels lost traction (whether it was accelerating too hard in the rain, or chirping the tires from a redline shift), so here's what I did. During the winter I take my car to an auto car wash as it's just too damn cold to wash my car outside. After I go through the auto wash, I would pull out doing these rugged burnouts. After a few car washes worth of burnouts, my traction control started kicking in again and functioning as normal. So now whenever I go to this car wash, I usually do a gentle burnout when pulling out just to make sure everything's cool with my traction control.

 

[epj3]

Elussive - that's not what you're experiencing. The reason you feel like it's slipping is becuase that rust takes off the layer of 'ash' that is caked on by the pad itself. Without this 'ash', the brakes wouldnt work efficiently. You're just feeling the 2 not-completely-mated surfaces trying to mate, which is why it works after a few stops.

ABS uses a round toothed wheel, and then a little magnetic pickup that senses when the teeth go by the sensor. It's how your speedometer works, how your tach works, how your abs works, how traction control works, and how dynamic stability control works - all from the same 4 - 8 sensors (depending on the car).

I'll post pictures to support my post in a minute.

 

[epj3]

Here is the front wheel bearing of an E46 M3 -- The teeth you see in the background is the wheel that I was talking about

I'm trying to find a picture of the sensor for the same car but if I can't find it - i'll just post the one from my car (it's the exact same design)

 

[epj3]

Here, it's number 21 (from etk)

that's the sensor (called a pulse generator by BMW) that picks up each time one of those teeth passes by it. Elussive - you cleaning your car has nothing to do with the ABS... the real way to test abs?? Slam on the brakes at 60 mph. If you hear a long screeching noise from your tires until you hit 0mph, then your abs sucks or didn't kick in - if you hear maybe a few chirps here and there, then your abs definitely works.

 

[epj3]

After I go through the auto wash, I would pull out doing these rugged burnouts. After a few car washes worth of burnouts, my traction control started kicking in again and functioning as normal. So now whenever I go to this car wash, I usually do a gentle burnout when pulling out just to make sure everything's cool with my traction control.

I can explain this!! Same thing happened with my car. What probably happened is that the sensor (a magnet...) probably had metal shavings all over it, and when washed the car (if you did an underbody wash) it probably pushed the shavings around that were stuck magnetically to the sensor, and then when you would drive, it knocked it off. The same thing happened with my ABS - I thought I had a bad sensor, so when i washed it off, it worked 100% and even better than before.