A vehicle remote function system is provided for determining a location of a fob relative to a vehicle. The system includes a controller adapted to be mounted in the vehicle and configured for communication with antennas mounted at different vehicle locations, the controller for use in determining the location of the fob based on ultra-wide band wireless signals transmitted between the antennas and the fob. The controller is configured to locate the fob within one of multiple three-dimensional zones, one of the zones configured to have a non-spherical shape. A method is also provided for use in a vehicle remote function system, the method for determining a location of a fob relative to a vehicle. The method includes transmitting ultra-wide band wireless signals between the vehicle and the fob, and determining the location of the fob within one of multiple three-dimensional zones, one of the zones having a non-spherical shape.