clearSelection

Clears the currently selected table rows or cells (depending on the current selection mode).

$("#grid").shieldGrid({
    dataSource: {
        data: [
            { ID: 1, name: "name1" },
            { ID: 2, name: "name2" }
        ]
    },
    selection: {
        type: "cell",
        multiple: true,
        toggle: false
    },
    columns: [
        { field: "ID" },
        { field: "name" }
    ]
});

function clearSelectedCells() {
    $("#grid").swidget().clearSelection();
}

Live demo of clearSelection function you can find here: clearSelection