A slick trick for more go in the snow!!
 

Most BMW since 1994 came with some form of "traction control" system - either ASC+T or DSC. When wheels slip or a loss of traction is detected, the traction control system automatically reduces engine RPM's and applies the anti-lock brakes if traction isn't restored quickly. The system does this much faster than a driver can usually react. While this is great for reducing or avoiding skidding and sliding in snow, ice, or on sandy shoulders, it can make it virtually impossible to get to the top of a slippery hill. Here's what happens: the rear wheels begin to spin. engine throttle is reduced, the anti-lock braking system kicks in and your BMW slows to a stop part-way up the incline. This happens even if you give yourself a running start.

You can disable the traction control by pushing the button on your console (labeled ASC pr DSC). When you do, the traction conttrol light will illuminate on the dash. But disabling the traction control doesn't always help. On a slippery hill with no ABS in play and full power going to the rear wheels, they will spin like mad. In a few conditions (e.g. fluffy snow), the fast spinning will allow the tires to burrow down to a surface where they can get enough traction to inch the car forward.... MAYBE. But on most slippery roads, all this does is cause the rear end or your BMW to slide sideways towards even bigger trouble. Woundn't be great if you could use the non-slip aspect of the ABS system without the reduction in power? Well.... you can. Heres how:

Push and hold the ASC or DSC button; the traction control light will illuminate for several seconds (about 10), then go off. Once the light is off, release the button. Your BMW's traction control system is now in a mode where ABS will be applied to wheels that lose traction, but the engine throttle will not be reduced!!

NOTE: Unlike normal traction control operation, where you can go from ON to OFF and back again just by pushing a button, once your BMW is in this "half mode", the only way to deactivate it is to turn the engine off. The next time you start the enigne, it will revert to normal mode (traction control ON).

I saw this in "Fast Times" the newsletter of Bavarian Autosport. Looking forward to trying it out this winter, Rob

Thanks for the tip!

Sounds like fun!

How is it reversed to regain the normal DSC settings?

Silver,

Our ski season has just finished, but that'll solve a lot of problems next year. I live in the snow during the season, and the X5 felt quite "loose" on packed snow/ice. Maybe that will help: I hope ;)

Thanks :D

Shut engine off and restart. :)

Very helpful, thanks!

Excellent! I wonder how many other tricks are hidden on our X5's?
Thanks

:thumbup: Swwweeet.

Thanks!

hm. i don't get it ........ so that basically means that the ABS will keep trying to work even with full engine power being applied????? that doesn't sound good ............ :confused:

that is awesome, thanks for the tip, will definitely be useful

I heard about that a while back and tried it last winter and it did not work. The dsc on my car is either all on or all off. NO in between mode. I did exactly what you siad too and it just didnt work

It didnt work when holding the button or after the light turned off?

I posted this in the same thread that posted in the Lounge:

http://www.xoutpost.com/203591-post7.html

Just to clear some misinformation in your post...when you push the button, DSC and related sub-systems are disabled, traction control remains functional. Holding the button down for an extended period of time does nothing. Engine power will no longer be cut by DSC. While the threshold for wheel-slip is increased, tractional control will still apply the brakes to prevent slip...only now, the function is to only prevent slip and not try to apply the brakes to simulate lsd-function of transfering power to the other wheel on the axle (ATB- Automatic Differential Brake).

In pre-xdrive models, power distribution front/back is basically fixed and can't really vary.

I don't know how the power distribution function changes with xdrive when you disable dsc, but I suspect that dsc is what controls it..so torque distribution ratio is probably fixed when you disable dsc.

i'll check it out this winter -- thanks for the tip!

Does this function work on pre-facelifted x5s? My X is 2001 made 4.4i.

This doesn't work (so I heard)

Holding the DSC in my 2001 made it disappear after a few seconds of holding it.

but I heard it doesn't change anyting?

I think this extra function is only on the x-drive model. In my 2003 pre-facelift it doesn't work. You can turn on or off the dsc. With dsc turned off the abdx is working, but not the reduction of power on the wheels

I tried my 2001 X5 4.4i today by pressing the DSC button for 10 seconds, then the DSC light went off. But have no idea if it works since I did not drive my X to climb hill.

Bump, any idea on if this will actually work?

I have an 05 4.4

Cheers

Dubs

Doesn't work on my 2004 X5 4.4i. You can disable DSC, which will allow *some* more slip than normal, but not a whole lot. It might disable the stability control, (I don't know, didn't try) but it certainly will not allow you to apply power with wheels spinning. I came to a dead stop with the throttle floored on a gravely hill-climb off-road.

I have talked with my BMW mechanic, and he says the next time I want to do this, I can get out, disconnect the wheel speed sensor on the RHS of the vehicle, and it will disable DSC, as it has no clue what's going on with one wheel, and shuts down the system. So it will not limit power when throttle is applied.

Please note that I've not tried this yet, but will the next time I'm in the off-road park. (I tow my Jeep Cherokee there to play...but sometimes it's fun to see what the BMW will do...within reason...)

I'll post back in a couple months when I try it.

Most snow and Ice ever in years here. I have used this method several times over this past winter in deep snow especially. What you mostly gain is is a little more wheel speed to dig out of a drift, or back out of one should you get in over your head. This is only meant to be done for short periods of time as the brakes are still actuating but the engine power is not being cut. Sometimes you just need the wheel speed, period. Not talking about ice conditions, wheel speed in not conducive to maintaining traction, so leave the system actuated for Ice. If you are driving in snow, and perhaps deep snow, you might have an advantage turning it off.

I have driven thousands of miles this winter and have become pretty adept at locating the button should I need less computer control. Don't get me wrong...it is a great system and saves more lives and keeps people heading in the right direction most of the time. That said, I have had to turn it off to actually get out of situations where the system just would not turn loose the power.

That said, simply, it works find on my 2005 4.4i X5.

The only time I needed to turn mine off was to allow more slippage and use the differential braking simulated LSD to get me through some really bad mud holes on the way to the hunting camp... worked a treat for my needs, kept me fromm getting stuck where the chevy trucks did. ;)

But look at post #15 for an accurate description of what's happening.

Agreed, Vig described it well. There are two modes (DSC, and then the DTC mode with higher thresholds of wheel slip). I have used that mode when in deep snow, to get moving, and then turned DSC back on as soon as the vehicle had some forward momentum.

There has been a lot of discussion about a third mode, obtained by holding the button pressed for some longer period of time. It never had any effect on my X5. It did work on my 2002 325xi, but those three modes were also documented in the owner's manual for that vehicle. Many posters believed that this applied to the X5, but I don't believe it ever did.

Can X get stuck with two side wheels?
 

Question:
Since the transfer case distributes torque/ power between front and rear differentials and the front/ rear differentials are mechanical - if DSC is switched off then does that mean if two same side wheels(FR & RR) spin(lose traction) then the vehicle will not get any traction?

i.e. although torque is being distributed front and rear, the differentials being mechanical cannot but spin the wheel with no torque since the opposite wheel is not being braked because DSC is de-activated.

thanks for your response.

Let's back up. DSC means stabilty control. It uses yaw sensors, steering angle sensors, etc, to determine if the vehicle is cornering properly, or if it is sliding. It uses the brakes (applied wheel by wheel) to help keep the car under control, within the limits of physics.

DSC includes a feature called DTC, dynamic traction control. DTC applies a brake to a spinning wheel, attempting to do what a limited-slip differential does.

When you turn off DSC, you still have DTC, but the engagement thresholds are changed, ie it allows more wheel slip before backing off the throttle. On my X5, it didn't turn itself off entirely, it stayed there, just not as aggressive on the intervention.

What you are asking is if DTC is turned off, and no, it isn't. Want to check? Turn off DSC, and the DTC light comes on. Churn your way up a snowy hill, with the wheels spinning. Then get out and smell the brakes. It may be difficult to find a snowy hill in South Africa, but perhaps a muddy hill would work.

You can still get the X5 stuck, it isn't an offroader with lockiing differentials, and most X5s do not have offroad tires so the tires tend to pack up pretty quickly. That is when you get to the limits of physics mentioned above. The x-drive system is designed to improve on-road performance and stability, not handle trails best left to a Jeep or Landrover.

This thread was originally started (years ago) with a suggestion that if you held the DSC button in, DTC was turned off entirely. Never worked on my X5, and it isn't mentioned in the manual. It was mentioned in my 325xi owners manual, and it did work on that vehicle. Somebody read an article in a BMW magazine, and assumed that it applied to the X5.

There's definitely no 'third' mode. You either have both stability and traction control, or just traction control. In any slippery situation - snow, soft sand, mud, etc - where the vehicle is prone to yawing and/or travelling in a direction other than that dictated by the steer angle, turning off the stability control will prevent unnecessary brake applications and give you a better chance of maintaining momentum and getting you out of the sh*t. You still have traction control which, as others have mentioned, mimics the function of an limited-slip diff.

I can say that the DTC helps in the mud with your foot down... if it were able to be fully turned off leaving me with open differentials front and rear I most likely ouwld have gotten stuck on the mud road to the camp.

Many thanks guy's - Once again the technical/intellectual capacity of this forum is astounding.
Here in Sunny South Africa we dont get much snow but we do have sand and I assume the traction issue is similar.

For soft sand you definitely need to disable the stability control for best results. The other tip is to lower your tyre pressures to around 18psi although this works better with higher profile tyres than with lower profile tyres. Be careful however of driving too hard in sand with low pressures otherwise you could roll a tyre off a rim.

For sure. No traction control = open diffs = easy to get stuck.

it works on mine 3.0 2001 december.....and this is how :)
YouTube - BMW X5 SNOW FUN DRIFT DONUTS
YouTube - BMW X5 SNOW BURNOUT Part 2

Aren't 4 wheel burnouts in ice/snow fun?!?

if you really want to save lives then use winter tires. all these issues then disappear...

those 'all season' tires are hard as hockey pucks below 45F (7C)!

Ohhh yeah man, it is lots of fun, cant call it burn out but it did make tires smell little bit :) you can spin it in smaller circle than rear wheel drive car, but is hard to get it spinning like that...DSC is ruining all fun :)


All season tieres...forget it...they ar enot good for summer or winter either...