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Vehicle properties
ADAS & driver assistance

EMERGENCY_LANE_KEEP_ASSIST_ENABLED

What it is

Enable or disable Emergency Lane Keep Assist (ELKA).

Set true to enable ELKA and false to disable ELKA. When ELKA is enabled, the ADAS system in the vehicle should be on and monitoring for unsafe lane changes by the driver. When an unsafe maneuver is detected, ELKA alerts the driver and applies steering corrections to keep the vehicle in its original lane.

In general, EMERGENCY_LANE_KEEP_ASSIST_ENABLED should always return true or false. If the feature is not available due to some temporary state, such as the vehicle speed being too low, that information must be conveyed through the ErrorState values in the EMERGENCY_LANE_KEEP_ASSIST_STATE property.

This property is defined as VehiclePropertyAccess.READ_WRITE, but OEMs have the option to implement it as VehiclePropertyAccess.READ only.

How the ID is built

A property ID is a 32-bit value packing four fields. Reading 0x1120100d apart:

FieldMaskValueMeans
Group0xf00000000x10000000SYSTEM
Area0x0f0000000x01000000GLOBAL
Type0x00ff00000x00200000BOOLEAN
Ordinal0x0000ffff0x0000100d0x100d

Reading it from an app

CarPropertyManager mgr = (CarPropertyManager)
        car.getCarManager(Car.PROPERTY_SERVICE);

boolean value =
        mgr.getBooleanProperty(VehiclePropertyIds.EMERGENCY_LANE_KEEP_ASSIST_ENABLED, 0);

This property can be read and written, though an OEM may implement it as read-only. It fires a callback whenever the value changes.