When I purchased my first BMW I was trying to mess around with all the buttons to test what exactly they do, that was until I pressed the DTC button on the dashboard; the car gave me a beep and a DTC logo lit up the screen. So how exactly this BMW DTC button functions?
DTC Light ON = Traction Control OFF
DTC Light OFF = Traction Control ON
Dynamic Traction Control (DTC)
When you press DTC button once and you get DTC light on means you have turned OFF the dynamic traction control but it will keep DSC running. Now you’re allowing wheel spin only if you’re driving forward but in case of any side slipping the car will not allow the spin to happen and that, of course, to prevent drifting.
Dynamic Stability Control (DSC)
Now it’s time for you to know about BMW DSC (Dynamic Stability Control) which is ON all the time by default and the purpose of it is to kill any wheel spin or drifting by modulating the throttle. How do you turn it off? (Not recommended for normal drivers) Hold the DTC button for 4 seconds will turn off DSC and DTC and it will allow any wheel spin or drifting.
BMW DTC & DSC
In conclusion, when you turn on your BMW you will have both BMW DTC and DSC running together, press once and you allow forward wheel spin, press for 4 seconds and you will allow drifting.
These technologies or functions allows you to control the wheel slippage but remember not to enter any corner too quickly regardless of what you have ON or OFF.