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. This part of SAE J551 specifies off-vehicle radiated source test methods and procedures for testing passenger cars and commercial vehicles within a Reverberation Chamber. The method is used to evaluate the immunity of vehicle mounted electronic devices in the frequency range of 80 MHz to 2 GHz, with possible extensions 20 MHz to 10 GHz, depending upon chamber size and construction. Three methods for calibrating and applying electromagnetic fields are described in the document: 1) Mode Tuned Reverberation Chamber method, 2) Mode Stir (Standard) Reverberation Chamber method and 3) Mode Stir (Hybrid) Reverberation Chamber method.