Circuit/System Description

The 12 volt start/stop system is used to reduced fuel consumption and emissions by automatically turning off the engine when coming to a stop and restarting when moving again. When coming to a stop assuming no disable conditions exist, the engine will automatically turn off at 5 km/h. The engine will automatically restart when the driver presses the clutch pedal (or releases the brake).

The 12 volt start/stop system can be enabled or disabled by the driver using the Autostop switch. The body control module applies voltage to the switch signal and monitors the voltage. When the Autostop switch is pressed, the signal circuit is pulled to ground and voltage at the body control module is low, indicating the switch has been pressed. The body control module also controls the Autostop switch indicator. When the 12 volt start/stop system is enabled by the driver, the body control module will illuminate the indicator by providing ground to the indicator control circuit.

The stop/start capacitor module is able to switch two double layer capacitors (stop/start capacitor) in series to the standard battery in case of high battery discharge currents (e.g. cranking events).