An apparatus is for detecting body diode conduction in a semiconductor device that includes first regions fixed with a substrate having an upper surface to establish a source, gate and drain with drain-to-source current flow parallel with the surface. The first regions experience body diode conduction in a first inter-region current flow among first involved regions. The apparatus includes: second regions fixed with the substrate and substantially similar in relative size and placement with respect to other second regions as a corresponding first region is in relative size and placement with respect to other first regions. The second regions experience model body diode conduction in a second inter-region current flow among second involved regions. The model body diode conduction occurs generally contemporaneously with the body diode conduction. Selected second regions are coupled with selected first regions to establish a connection locus to permit detecting the model body diode conduction.