User proximity detection for activating vehicle convenience functions

Abstract

A convenience controller activates a small zone high location precision welcoming detecting function (with high current utilization) in response to a detected arrival of an authorized user into a larger zone low location precision welcoming detecting function (with low current utilization) approach region around a vehicle. A short range transmitter broadcasts a polling signal covering the region. The short range transmitter has an approach pending mode wherein the polling signal is broadcast according to a first predetermined repetition and a baseline mode wherein the polling signal is broadcast according to a lower repetition. The short range transmitter has a first power drain in the approach pending mode. A wireless communication system is configured to monitor for user activity outside the approach region corresponding to a potential user entry into the approach region, wherein monitoring by the wireless communication system has a lower power drain. If the short range transmitter is in the baseline mode when the user activity is detected, then the short range transmitter switches to the approach pending mode.