semiatic

Lane assist (lane keeping) light

Shows the state of the lane keeping system, which watches the road markings with a camera behind the windscreen and steers gently or warns when the car starts to drift out of its lane. Green: switched on and able to work. Amber/yellow: switched on but not helping you right now, switched off, or faulty — which one depends on the make.

GreenYellow / amber

Not defined by regulation: a maker convention

What to do

Green needs nothing, but keep steering: the system only assists. Amber/yellow means it is not helping, so steer fully yourself. It often comes back when the markings are clear again; if it stays amber with a fault message, or stays on after you have cleaned the windscreen in front of the camera, have it checked.

Makes differ: what this light means on your car, the other colours it may use for the symbol and what the car wants you to do are set by the manufacturer, so your car's owner's manual is the authority.

Symbol
Lane markings running away from you, dashed line in the middle
Colour
Green or Yellow / amber
Standard
None — a maker convention, described here from 2 makers: Volkswagen, Hyundai

Where makes differ

Volkswagen's lamp is green when the markings are detected and amber when they are not. Hyundai's Lane Safety light is grey when conditions are not met, green when they are, blinks green while it is steering, and turns yellow only when the function is switched off, disabled or faulty. So an amber lane light means 'no markings seen' on one make and 'off or faulty' on another.

Not defined by regulation: a maker convention

Neither US FMVSS 101 (Tables 1 and 2) nor UN Regulation No. 121 lists this light, so no rule fixes its symbol or its colour. What follows is what the makers cited below say; other makes, and other model years of the same make, may draw it differently.

Neither FMVSS 101 nor UN R121 lists a lane-keeping tell-tale.

Other green maker lights

Adaptive cruise control (ACC) lightSpeedometer dial with a needle · also yellow / amber · maker conventionAUTOHOLDAuto Hold lightThe words AUTO HOLD · also yellow / amber · maker conventionHill descent control lightCar pointing down a slope · also yellow / amber, red · maker conventionAAuto stop-start lightLetter A inside a circular arrow · also yellow / amber · maker convention

All green dashboard lights, regulated ones included

Other yellow / amber maker lights

Diesel particulate filter (DPF) lightBox full of dots with a pipe at each end · maker conventionAdBlue (DEF) warning lightLiquid container with a wavy fill line and a drop · also red · maker conventionEPCEPC (electronic power control) lightThe letters EPC · maker conventionForward collision warning lightCar seen from behind with radar arcs around it · also red · maker conventionBlind spot monitor lightTwo cars side by side with signal waves between them · maker conventionAdaptive cruise control (ACC) lightSpeedometer dial with a needle · also green · maker conventionAUTOHOLDAuto Hold lightThe words AUTO HOLD · also green · maker conventionPower steering warning light (EPS)Steering wheel, sometimes with an exclamation mark · also red · maker conventionWater in fuel light (diesel)Fuel pump with water drops beside it · maker conventionGearbox (transmission) warning lightCog wheel with an exclamation mark · maker convention?Key not detected lightKey with a question mark · maker conventionBulb failure (exterior light) warningLight bulb with rays and an exclamation mark · maker conventionHill descent control lightCar pointing down a slope · also green, red · maker conventionAAuto stop-start lightLetter A inside a circular arrow · also green · maker convention

All yellow / amber dashboard lights, regulated ones included

Sources

No regulation defines this light, so it is described from 2 carmakers' own manuals or owner pages, each fetched and checked on the date shown:

Written in our own words; the makers' pages cover their own models only.