Stops accidental powertrain engagement by adding conditions to when the power unit can be engaged.
Where powertrains are controlled by wire (i.e. electric, hybrid, automatic start-stop or start-by-button), vehicles must put more restriction in to prevent accident over-ride of control by humans or other systems.
A typical system may require the driver’s seat to be in use (seat weight sensor, driver gaze camera monitor), or the clutch or brake pedal to be depressed.
Let’s say you’re in traffic, the engine stops automatically but the traffic jam is heavy so you get out. Without this, Traffic Jam Assist might then drive off without you, the driver, when the traffic starts to clear.