ECU supervise the system function, light the fault indicator to alert driver when any error.

ECU对系统的功能进行监控，如果发现故障，将点亮系统故障指示灯，提示驾驶员系统有故障。

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Ford's outfitted the Fusion Energi with a dizzying array of driver-assist tech, including a lane-keeping system, adaptive cruise control, driver alert system, active park assist, rear camera, blind-spot indicator system with cross-traffic alert and pull-drift compensation (phew).

ENGADGET: Ford Fusion Energi plug-in hybrid test drive (video)

When the system recognises that a lane departure is imminent, it bleeps or flashes to alert the driver.

ECONOMIST: Motoring