DCT (Traction Control) Button Effects

[dtla1]

I know what the purpose of the DCT button is. Press it once and the traction control is backed off a bit and will let you have a little fun, press and hold and traction control is completely off.

Now what I didn't know it would do.
I've noticed that while driving, if you have traction control all the way on (no button press, no dct light) and then keep your foot on the throttle at a cruising speed, and press the dct button (light on), throttle response seems to die off a little. Press it again (light off) and the response comes back.

Anyone else notice this? Maybe try it for me when your'e driving today, is it just my car?

Thanks.

[bmw0bsession]

If you have the Sport button on or off and you turn off the DTC, for safety purposes it softens the throttle response so you do not easily spin out or whatever reason. That is why you feel like it backs off some. All our cars do this.

[e36addict]

Originally Posted by bmw0bsession

If you have the Sport button on or off and you turn off the DTC, for safety purposes it softens the throttle response so you do not easily spin out or whatever reason. That is why you feel like it backs off some. All our cars do this.

This. It's just idiot-proof.

[dtla1]

Does that really make any sense though?
I can't think of a situation where this would actually happen.

So you're taking a sharp turn fast, when all of a sudden you reach over and hit the button?

[Tricki]

.

[Chunner]

A lot of mis-information here. Here it is, DTC and DSC fully explained.

Dynamic Traction Control (DTC) allows more wheel slip and thus a more dynamic driving style with higher wheel traction and DSC controlling stability. A small amount of spin on the drive wheels improves traction when pulling off from a standstill in snow or on loose terrain.

Dynamic Traction Control (DTC) is a sub-function of the Dynamic Stability Control (DSC) system that can be turned on and off. DTC has two major roles: to regulate traction and to enable sports-style driving while providing active stability control. When the drive wheels start losing traction the DSC automatically begins stabilisation measures. The Dynamic Stability Control system curbs the engine output and stops slip on the wheels. In exceptional situations, however, a small amount of wheel slip can be an advantage.

When driving in deep snow, slush or on loose terrain a small amount of wheel spin improves traction. For these occasions, as well as those when the drivers want a sportier driving style, the DTC can be activated by pressing a button and this allows more slip and reduces the DSC’s curbing of the engine. The result: better traction and more thrust.

The DTC also makes driving on snow and ice-free roads more dynamic. When activated, the DTC allows sporty drivers more room to manoeuvre around curves than the Dynamic Stability Control and even permits controlled drifts. The driver retains complete control over the vehicle in every situation and the Dynamic Stability Control’s stabilising measures remain active even when the DTC is activated.

DSC is ON by default, there is no need to press any buttons on start up. DSC uses a series of sensors to detect wheel spin, yaw rate of the car and other properties. Using sensors and other electronics it can apply the brakes as needed, cut engine power and with Active Steering it can make small steering corrections to better keep the car under control. In layman terms, all the nannies are on by default andhelp to keep the car from spinning out. When DSC is intervening a caution light will flash in the instrument cluster.

In some models, DTC (Dynamic Traction control) is a sub-function of DSC. It is activated by briefly pressing the DTC button. A light will light up in instrument cluster indicating this function has been activated. DTC will allow the wheels to spin, increases the angle at which the system will begin to apply the brakes (eliminates the yaw rate sensors) and does NOT cut the engine power. This system function is designed to allow the driver to spin the wheels in order to get through snow, ice and other conditions where wheel spin is required. While certain sensors are deactivated others still remain active. This function also provides a more sporty driving experience in dry conditions while at the same time being a limited security blanket. Having some track time messing with this system, DTC will still cut in and apply braking so you can ‘t get the back end out all that much but it still allows you full power to motor through. Like DSC a blinking caution light indicates the system is intervening.

DSC/DTC can be turned OFF by holding the DTC button for 3 seconds. The caution indicator light (as Shown above) will remain lit in the instrument cluster, the nannies are now off and you are on your own so stay within your abilities!

A function of the DSC system that does remain active even when everything is OFF is the e-Diff. 1 series cars and those 3ers produced after March 2008 include this. With the launch of the latest generation 7 Series and 5 Series, xDrive equipped vehicles also now features this and the ability to vector drive power to the outside wheel through use of braking force. The e-Diff essentially mimics the concept of a limited slip differential (LSD). It accomplishes this by applying braking to the spinning wheel and thus transferring more power to the wheel with better traction. It will allow you to leave strips if you are so inclined. This feature is also active in DTC mode.

While DSC and its companions provide you with an extra level of safety it is important to remember that no electronics, no matter how sophisticated, can over come the laws of physics and driver ability. In other words, drive safe and within your ability and exercise caution in less than ideal road conditions.

[bmw0bsession]

When you push the power I push then it can be hazardous but it truly isn't lol. just bmw preventing law suit

[bmw0bsession]

Originally Posted by dtla1

Does that really make any sense though?
I can't think of a situation where this would actually happen.

So you're taking a sharp turn fast, when all of a sudden you reach over and hit the button?

or if its raining out too

[3002 tii]

Originally Posted by bmw0bsession

When you push the power I push then it can be hazardous but it truly isn't lol. just bmw preventing law suit

Que???

[Tricki]

Originally Posted by dtla1

I know what the purpose of the DCT button is. Press it once and the traction control is backed off a bit and will let you have a little fun, press and hold and traction control is completely off.

Now what I didn't know it would do.
I've noticed that while driving, if you have traction control all the way on (no button press, no dct light) and then keep your foot on the throttle at a cruising speed, and press the dct button (light on), throttle response seems to die off a little. Press it again (light off) and the response comes back.

Anyone else notice this? Maybe try it for me when your'e driving today, is it just my car?

Thanks.

Ok ....I have just purchased my 2nd 135i. It's a 2013 build.

I had a 2011 135i previously and had the exact same issue. Sport on and when you press dtc to have fun, you would lose the aggressive throttle response.. I complained to no avail.

The 2013 car I have, this problem doesn't exist.... Dtc on or off it doesn't matter it's the sport button that controls the aggressiveness .... The way it should be on your car.

I can't explain it, unless the new dme program solves it not sure but now I know this I would fight it..

Good luck

[e36addict]

Originally Posted by Tricki

Ok ....I have just purchased my 2nd 135i. It's a 2013 build.

I had a 2011 135i previously and had the exact same issue. Sport on and when you press dtc to have fun, you would lose the aggressive throttle response.. I complained to no avail.

The 2013 car I have, this problem doesn't exist.... Dtc on or off it doesn't matter it's the sport button that controls the aggressiveness .... The way it should be on your car.

I can't explain it, unless the new dme program solves it not sure but now I know this I would fight it..

Good luck

I've noticed this on the newer cars.. I think they changed it some time in the 2012 model year. The DTC button is different, the light in the cluster is different, and a little "TRACTION" indicator pops up in the cluster next to the gear indicator. Unsure of what changed in the traction system if anything, but it doesn't affect the throttle response like it does in older cars.

[Javbrat-wp]

hi there, thanx for this ... i have been asking this question from the time i bought my car but not even the dealer could explain or find any solution to this. i have a n55 2011 dct and with ppk2.

[sam-e82]

Originally Posted by e36addict

I've noticed this on the newer cars.. I think they changed it some time in the 2012 model year. The DTC button is different, the light in the cluster is different, and a little "TRACTION" indicator pops up in the cluster next to the gear indicator. Unsure of what changed in the traction system if anything, but it doesn't affect the throttle response like it does in older cars.

This is strange as I have the newer logos but throttle is affected by pressing DTC on/off. It only started with the lag s/w update so I think it is caused by the newer software, as the logos were changed through the update for me.