Honda Civic Owners Manual: Lane Departure Warning Function

Lane Keep Support Function

Provides assistance to keep the vehicle in the center of the lane. When the vehicle nears a white or yellow line, steering force of the electric power steering will become stronger. ...

When the System can be Used

The system can be used when the following conditions are met.  The lane in which you are driving has detectable lane markers on both sides, and your vehicle is in the center of the lane. ...

See also:

Honda Civic Owners Manual. If the Malfunction Indicator Lamp Comes On or Blinks
Reasons for the indicator lamp to come on or blink  Comes on when there is a problem with the engine emissions control system.  Blinks when engine misfiring is detected.  What to do when the indicator lamp comes on Avoid high speeds and immediately get your vehicle inspe ...