Method, controller and system for an implantable medical device capable of delivering therapeutic stimulation through a plurality of electrodes. A control module is operable to conduct a plurality of measurements of impedance values creating a plurality of measured impedance values for a plurality of selected sets of individual ones of the plurality of electrodes based on a plurality of active parameters. The control module conducts the plurality of measurements of impedance values in a plurality of stages in which at least one of said plurality of active parameters is varied between individual ones of the plurality of stages.