Vehicle electrical/electronic systems may be affected when immersed in an electromagnetic field generated by sources such as radio and TV broadcast stations, radar and communication sites, mobile transmitters, cellular phones, etc. Reverberation method is used to evaluate the immunity of electronic devices in the frequency range of 500 MHz to 2.0 GHz, with possible extensions to 200 MHz and 10 GHz, depending upon chamber size and construction. Optional pulse modulation testing at HIRF (High Intensity Radiated Fields) test levels, based upon currently known environmental threats, has been added to this revision of the standard. This document addresses the Mode Stir (Continous Stirring) Reverberation testing method which has been successfully utilized as a design and production stage development tool for many years. The Mode Tuned (Stepped Tuner) Reverberation testing method is covered in the SAE J1113-28 document.