Lane Departure Warning Light

Can I keep driving?

What to do right now

1. 1Check your road position and make sure you are staying safely inside your marked lane.
2. 2Turn on your wipers and washers if the windscreen is dirty or smeared in front of the rearview mirror.
3. 3Use your indicators before changing lanes to stop the warning light and buzzer from activating.
4. 4If the light stays steady amber, pull in somewhere safe and check for dirt, ice or mist on the glass.

Likely causes

Most likely first.

1. Likely

   Blocked windscreen camera

   Dirt, salt spray, road grime, frost or internal condensation directly in front of the camera housing behind the rearview mirror blocks its view of the road markings.

2. Likely

   Drifting across road markings without indicating

   The forward-facing camera detects the tyres crossing lane markings when the indicator is off, triggering the alert to warn of unintended drifting.

3. Possible

   Obscured or missing road lines

   Worn paint, standing water, heavy snow or sudden changes in tarmac texture can confuse the software, causing the system to disable itself until clear lines return.

4. Possible

   Camera calibration loss after windscreen replacement

   If a new windscreen was fitted recently without realigning the optical sensor, the camera cannot accurately measure the vehicle's position on the road.

5. Rare

   Blown fuse or camera module failure

   An electrical fault, loose wiring harness plug or internal camera circuit failure prevents the driver assistance computer from communicating properly.

What you can check yourself

Park somewhere safe and level, engine off, before you start.

1. 1

   Clean the upper windscreen

   Park safely with the engine off and clean the glass directly in front of the rearview mirror using glass cleaner and a microfibre cloth. Remove any dried insects, tree sap or road grime that blocks the camera aperture.

2. 2

   Demist the front screen

   Start the engine and switch on the front windscreen demister with air conditioning enabled. Clearing trapped interior condensation or frost from the camera housing often clears a solid amber light within minutes.

3. 3

   Check the lane assist button

   Look for a button on the dashboard, indicator stalk or steering wheel showing a vehicle between lane markings. Press it once or check your instrument cluster menu to ensure the feature was not accidentally switched off.

4. 4

   Inspect recent windscreen work

   Look closely around the rearview mirror bracket from inside and outside the vehicle for loose plastic trim, detached cables or misaligned brackets if your windscreen was replaced recently. Any gap or loose sensor requires professional recalibration.

Typical prices in Ireland (€) and the UK (£), from an independent garage up to a main dealer. Prices vary mostly based on whether the camera simply requires electronic target recalibration or full component replacement followed by dealer programming.

When to go to a garage

• The amber warning light stays on constantly across multiple journeys even after thoroughly cleaning and demisting the windscreen.
• The warning light comes on alongside other safety system warnings such as power steering, stability control or autonomous emergency braking.
• The lane departure system activated abruptly or pulled at the steering wheel when you were driving centred in a clear lane.

Questions drivers ask

Test rules here are for the National Car Test in Ireland (NCT) and the MOT in the UK. Elsewhere, check the regulations of your own country or state before going for a vehicle test.