I saw something new this morning. I pressed the DSC button near the shifter there's a new messege on the IDrive screen and the messege on the dash board.

When i pressed it, the messege on the IDrive says "DTC activated, DSC limited" and "DTC" shows up near the odometer.
This wasn't the case before the software upgrade. Before it used to give me a warning light that said DSC was off. Now DSC is "limited".

I know DSC is Dynamic Stability Control but what is DTC?

Teriyaki

 

I think it is Dynamic Traction Control, kind of a sub-system of the whole Dynamic Stability Control. To fully turn off DSC, you have to hold down the DSC button for a full minute or something like that. Just the quick press turns off the Traction Control.

 

From the manual:

"When DTC is active, DSC provides only limited system response up to a speed of approx. 45 mph/70 km/h. Control intervention for stability-enhancement is reduced"

In other words with DTC active you have limited stability (only traction control) - sort of like cars that only have traction control on/off. So the entire DSC is thus limited to only traction control. This traction control is stonger than the normal traction control when the full DSC ssytem in on. When DSC is fully on, you have traction control AND braking control to individual wheels, etc. The full system DTC + DBC.

 

What am I gaining by keeping DSC/DTC on?
What am I losing by turning it off?

 

DSC on = you are letting the car use traction control (DTC) and braking control (DBC) to correct over/understeers, spins, etc.

DSC off = you are in charge now to correct for under/oversteers, spins, etc.

Unless you are well versed in car control and understand how to use the brake, gas pedal, and steering wheel to control the car should it go into an under/oversteer, spin, etc., I would advise leaving DSC on. I myself had (in previous cars with similar mechanisms) at times left it on and at times (when I wanted to control everything) left it off. But you need to be careful if you turn it off.

DTC is useful if you don't want wheelspin.

 

Here's a link to another thread on this topic<---.

 

If this feature is useful, why would you not want to have it on at all times? A better question woudl be why would you include an option to turn it off?

Teriyaki

 

Depends on whether you want to drive the car or the computer drive for you...

If you're on a 'track day' you'll want to turn it off

If you're driving around town then you'll want it on unless you want to pull donuts

 

Because it may not be useful all the time. If you are stuck in snow, you want more traction control so you turn on DTC at the expense off less DSC (DTC + DBC).

Or if you're like me or others, at times it can get it the way. I learned how to correct for spins, oversteers, understeers, etc. when I used to race in SCCA. When driving street cars, I found that I had to fight with the car to correct, which would sometimes cause on overcorrections which wasn't good. The car would try to do its thing and I would try my thing and we'd be both fighting the problem which was no good. As I got more used to them I left them on mostly. You just have to learn the system, but in general there is no need to really turn it off unless you are driving hard and want to be 100% in control. For 90% of situations I'd say these modern systems are pretty damn good. For the other 10%, if you're there , you better know what you're doing!

Anyway, I bet as they improve the will be standard w/o an on off switch - like ABS. Remeber when we didn't have ABS and had to modulate the brakes in wet/slippery conditions?

I should add that true sports cars should always have the ability to turn this on or off. BMW considers the 5 a true sports car - more so than me I guess!

 

I wanted to add that the reason I don't like Active Steering is for a similar reason. I wish I could turn it off or on. Then maybe I'd get the chance to get used to it. I don't like the fact that I have to dial in opposite lock of varying degrees as my speed varies - just seems counterintuitive to me. If AS had an on/off I would have gotten it with the sports pkg and messed with it on to learn it and see if I could get used to it.