Fits: 2008-2016 Buick Enclave 2009-2016 Chevrolet Traverse 2007-2016 GMC Acadia 2007-2010 Saturn Outlook What is an ABS Sensor? The anti-lock braking system uses an ABS sensor or wheel sensor to monitor the wheel speed and send this information to the ABS computer. The ABS computer uses this information to prevent the brakes from locking during an emergency stop. Without ABS, a wheel will automatically lock up in slippery and/or gravel-like conditions, as well as potentially experience a loss of directional control and vehicle stability. Where are these Sensors Located? .