1. A method comprising: scanning, by a processing device, a first set of electrodes in a first dimension of a capacitive sense array to measure self-capacitances of the first set of electrodes, using a first dimension multiplexer to route measured signals from the first set of electrodes to receive channels of the processing device, wherein a shield signal is routed through a second dimension multiplexer to a second set of electrodes in a second dimension; identifying, based on the measured self-capacitances of the first set of electrodes, the presence of an object in proximity to the first set of electrodes and the capacitive sense array and not in physical contact with the capacitive sense array; responsive to identifying the presence of the object based on the measured self-capacitances of the first set of electrodes, configuring the capacitive sense array to measure a mutual capacitance of at least the first set of electrodes and the second set of electrodes by routing a transmit signal through the first dimension multiplexer to the first set of electrodes and routing measured signals from the second set of electrodes to the receive channels of the processing device; and scanning, by the processing device, the first set of electrodes and the second set of electrodes of the capacitive sense array to measure mutual capacitances of intersections between the first set of electrodes and the second set of electrodes to determine a location of the object.