The purpose of this study is to accurately measure quantum efficiency of a single-junction crystalline silicon cell within a module using a non-intrusive methodology. This novel procedure for measuring the quantum efficiency for a specific location on a cell within a module will be referred to in this paper as cell-module quantum efficiency (C-M-QE). This paper will describe the equipment and conditions necessary to measure C-M-QE and discuss the factors that can influence this measurement. The ability to utilize a non-intrusive test to measure quantum efficiency of a cell within a module is extremely beneficial for reliability testing. Detailed methodologies for this innovative test procedure are not widely available in industry because equipment and measurement techniques have not been explored extensively. Results and conclusions provide the overall accuracy of the measurements and discuss the parameters affecting these measurements.