[runrider]

How does DTC limit slippage?
Does it limit the throttle, does it transfer power from a slipping wheel to the other wheel(s) at the diff, or does it apply the brake to whichever wheel slips?

Does it use a combination of these methods? Are all modern 3-series engineered to accomplish this in the same way?

Thanks in advance.

[FLA 335]

in short it cuts power from the engine until the wheels are back in sync (front and back). it wont allow the rear wheels to spin, it will cut power before this happens... Also, there is DTC and DSC...

DTC wont allow for wheel spin period...

DSC wont allow the car to slide when taking turns..

when you press DTC once... you turn DTC off which will allow for wheel spin, but if the back slides DSC will cut in take away power and apply braking...


yes braking is applied to my knowledge... i have only had this vehicle but i am going based on research and reading numerous threads...


Search... is your friend... but i hope i was able to help...

[VTECaddict]

Actually, pressing the DTC button once turns DTC ON. The message in the iDrive shows "DTC activated, DSC limited!"

Turning ON DTC allows for some wheel spin.

The default mode is DSC fully on. DTC is basically a synonym for restricted DSC (think of it sort of like M-dynamic mode for non-M cars). So by turning on DTC you are turning off part of DSC. Pressing and holding the DTC button will turn everything completely off.

[radix]

Originally Posted by VTECaddict

Actually, pressing the DTC button once turns DTC ON. The message in the iDrive shows "DTC activated, DSC limited!"

Correct, plus DTC does allow for some wheel slippage IIRC.

[DJKhan85]

Originally Posted by FLA 335

in short it cuts power from the engine until the wheels are back in sync (front and back). it wont allow the rear wheels to spin, it will cut power before this happens... Also, there is DTC and DSC...

DTC wont allow for wheel spin period...

DSC wont allow the car to slide when taking turns..

when you press DTC once... you turn DTC off which will allow for wheel spin, but if the back slides DSC will cut in take away power and apply braking...


yes braking is applied to my knowledge... i have only had this vehicle but i am going based on research and reading numerous threads...


Search... is your friend... but i hope i was able to help...

DTC will not cut as much engine power as DSC. Only DSC will cut engine power fully. DTC will only apply braking to the rear wheels in case 1 wheel starts spinning more than the other wheel or if both wheels start spinning. This is to make sure power gets distributed instead of spinning away since we have open differentials. I got to see this in action when I couldn't get up a snowy hill with dsc on but dtc allowed me to get up the hill just fine.

DSC will use DTC and also limit engine power as well as selectively braking any wheel to stop the vehicle from going sideways. That includes the front wheels.

here is a video that describes the features.

[VTECaddict]

To answer the OP's question, in full DSC mode the computers will cut power and brake individual wheels to try to restore traction and keep you going in your intended direction.

The system does not have any torque vectoring capabilities to power the opposite wheel. xDrive in the X6/X6M/X5M does have torque vectoring (Dynamic Performance Control) though.

[FLA 335]

i stand corrected.. i had some of the stuff right though... hehehe...

still learning...

[runrider]

Thanks DJkahn and vtecaddict. That was the answer I was looking for! I thought the E90 had LSD when I bought it. Big frowny face.

[Top_Gear_Fan]

Do our 3 series have ESP?

[runrider]

Originally Posted by Top_Gear_Fan

Do our 3 series have ESP?

Yes, my car seems to read my mind all the time!


ESP is another way of saying DSC.

[VTECaddict]

Yeah, almost every company has their own acronym or name for stability control. ESP, ESC, DSC, VSA, VSC, VDC, etc, etc

[DJKhan85]

Glad I could help guys. You should try out each mode(DSC,DTC, and all off) in an empty parking lot in the rain or snow. It's really astounding how the car handles differently in each mode. It's really like driving another car. If you mange to lose control with DSC on, well, you're boned lol.

[DJKhan85]

Originally Posted by runrider

Thanks DJkahn and vtecaddict. That was the answer I was looking for! I thought the E90 had LSD when I bought it. Big frowny face.

if you have a march 08+ vehicle then you have whats called an eLSD. It functions sort of like DTC except it doesn't cut engine power and just uses the brakes to try and modulate power between both wheels. It is a "feature" of the 1 series that BMW later slipped into the 335's.

[joyride08]

So why would you need to turn DTC on? It's on by default, you need to deactivate it by pressing once and/or holding for DSC & DTC off. Hence the warning lights on the dash.

When i want to launch hard, press once == allows for wheel spin, when on by default, not pressing anything, power is cut when wheel spin is detected.

[VTECaddict]

DTC is not on by default. DSC is on by default.

[HRC]

Originally Posted by VTECaddict

Actually, pressing the DTC button once turns DTC ON. The message in the iDrive shows "DTC activated, DSC limited!"

Turning ON DTC allows for some wheel spin.

The default mode is DSC fully on. DTC is basically a synonym for restricted DSC (think of it sort of like M-dynamic mode for non-M cars). So by turning on DTC you are turning off part of DSC. Pressing and holding the DTC button will turn everything completely off.

Danny

[fdsasdasdf]

http://www.e90post.com/forums/showthread.php?t=346498

[MrDummy]

Just hope we dont have the same electronics as a lexus and we will be fine

DOH! TOO SOON?




And I have only used the DTC ON feature a few times on snowy roads and it works awesome as well as the AWD set up on my XI

[Verbiage]

I actually didn't know how to differentiate between the two until reading a lot of the very insightful comments on this thread. It actually works pretty well in the snow (with DTC enabled, which I seemed to have found out the hard way). Thanks guys

[3lusive]

Originally Posted by joyride08

So why would you need to turn DTC on? It's on by default

Again, DTC is deactivated in normal conditions. DTC can be useful in winter weather conditions because some winter tires may need more wheel slip for maximum traction. With DTC off the car will restrict the wheelslip and not allow for the maximum traction.

[joyride08]

So everyone says it's OFF by default. What happens when you, start car, rev motor to 4000 RPM and let out clutch? Engine cuts power to try and regain traction, at least it does in my car. Every time! Same thing happens when accelerating on bumpy road and traction become unstable

Do the same thing by pressing the DTC button, light shows up on dash, allows for wheel spin, no power is cut. Unless DSC engages...

Maybe it's terminology.. but the function i'm describing is correct?

[joyride08]

Ah.. i guess i've never heard of a traction system that allows for More wheel-spin then normal everyday driving. To me, wheel-spin means less traction. But oh well..

Thanks!