Since vehicle fires associated with electrical failures take place frequently all over the world, auto engineers have been making great efforts to solve the problem, but most of the efforts are only focused on the wiring improvement, which is not enough. In order to eliminate these fires, the author had devised an electronic circuit protector, the Semiconductor Breaker/Relay (SBR). Based on a modified SBR, several other control devices, such as the Voltage and Current Adjustor of the Generator (VCAG), the Semiconductor Start Relay (SSR), and the Semiconductor Protection and Control System (SPCS) of vehicle circuits, have been presented in this paper. If these new control devices are widely applied in vehicles, the fires caused by short circuit will be avoided because the circuit breaking control of SBR is fast and accurate; the battery service life will be extended because of the cyclic charging control effect of VCAG; and engine cold start emissions will be decreased because of the lower power consumption and the faster reaction of the catalytic converter during a cold start. By analyzing and comparing with the traditional circuit protection method, the reliability of the new technology is proved to be better, and the cost will not increase more. Further tests are still needed for the detailed numerical values about how long the battery service life will be extended and how much the cold start emission will be deceased by adopting the new technology of SPCS.