1) Update Traktor
To enable jog wheel/scratch functionality, first make sure that your software is completely updated.
Keep in mind, your version of Traktor will need to be 2.1 or higher.
2) Adjust the jog wheel sensitivity on your controller
- Find the jog wheel sensitivity dials on the front left of your controller (they're marked Touch Sensor L, Touch Sensor R)
- Turn the dial till the light blinks, then slowly adjust backwards, just until the light stops blinking
- Repeat for other jog wheel