An engine start/stop control system for preventing an engine from stopping when
a vehicle is traveling. The system includes an IG1 driver circuit arranged
between a power supply control unit and an IG1 relay. The IG1 driver circuit
is activated in accordance with an activation signal from the power supply control
unit or an output signal of a latch circuit and includes an FET for activating
a relay. The latch circuit keeps the FET ON and the relay activated unless the
vehicle stops traveling and a start/stop switch is pushed.
