If you notice that your PlayStation 3 controller is constantly scrolling to the left, there may have been an issue when the controller was paired with the system. When you power on a console and the joysticks or buttons of a controller are pressed, the console reads this as the default positioning. A left-pressed directional pad or joystick translates to the PS3 constantly pressing left. Fixing this is simple, just a matter of re-pairing the controller and console.
Power off the PS3.
Plug the included USB cable into the port on the back of the PS3 controller. Plug the free end into the USB port on the front of the PS3.
Power on the PS3. Do not press any buttons or joysticks on the controller as the system boots up. Ensure that all buttons are in their default position (i.e. the controller is not upside down or leaning against something, pressing down a button or joystick).
Press the “PS” button in the center of the controller. A red indicator light will blink for a few seconds as it pairs with the system. When the red indicator light becomes solid, you can disconnect the USB cable. After the controller has been properly re-synced with the system, you should no longer have issues. If you continue to have issues, the controller may need to be replaced.