Auto light Dip/Full Beam Issue

[Simon DW]

Hi all,

Last night on the way home my auto dip/full beam just did not work, it would not dip at all also the lane change warning came on and stayed on continuously without any audible sound, normally bleeps when you cross the white line in the middle of the road. At one point I could not put lights on full beam manually! Eventually it sorted itself out, is there a re-set for this kind of malfunction, anyone experienced this before?
The conditions were very cold and had a frost on the car when i started it. I will have to monitor it and see what happens, its not the first time this has happened either.

[anchorman]

Yeah, mine did it once. They can become confused in certain atmospheric conditions when moisture forms near the lenses. I didn't bother and just turned them on manual but sometimes if you stop and turn the ignition off then back on, they reset themselves. I've got a TSB I'll dig out.

[jtonline]

Lane change warning malfunction light coming on can be caused by mist/frost on the windscreen area behind the rear view mirror where the sensor looks out at the road ahead. It's happened on mine on occasions. I don't have the auto dip on my headlights but as anchorman says it's probably the same issue with the sensor in the headlights being confused by a layer of frost which doesn't melt as quickly on LED light lenses as it does with halogen lamps.

[santa]

I've experienced this as well.
I have a certain stretch of road where the LDW warning light comes on and when that light is on the auto dip/fullbeam doesn't work.
I can switch thefull beam on manually but they don't go to dipped when I meet a car.
As soon as the LDW warning light goes off (and LDW is working normally again) the auto dip/fullbeam works again.

I have no idea why the warning comes on on this specific stretch of road. If it can't see any lines it should just deactivate the LDW.
Maybe something confuses the system.

[anchorman]

I wonder if strong electrical fields effect these systems. My DAB won't work passing under high tension wires.

[st3v3cx-3]

The LDW and auto dip / full beam switching are both controlled by the same camera. The Forward Sensing Camera (FSC) determines the conditions ahead of the vehicle while travelling at night and detects traffic lanes. The following systems also use the Forward Sensing Camera (FSC) :-

- High Beam Control system (HBC)
- Lane Departure Warning System (LDWS)
- Smart Brake Support (SBS)

The timing in which the system switches the headlights changes under the following conditions (some but not whole lot in the manual) :-

- When there are reflective objects in the surrounding area such as reflective plates and signs.
- When visibility is reduced under rain, snow and foggy conditions.
- When driving on roads with sharp curves or hilly terrain

If the LDW warning light is turned on, it indicates a possible malfunction of the system. Perhaps this happens when the forward sensing camera isn't functioning properly due to the conditions above and thus both the auto dip / main beam switching and LDW will be affected at the same time.

[jtonline]

Yes, I was mistaken when I said the HBC sensor was in the headlight, (it says it is on this Mazda page) however, on the CX-3 it does in fact use the FSC. The FSC definitely gets confused (understandably) by frost/mist on the windscreen, which causes the malfunction light to come on. In my experience, the LDWS malfunction light comes on briefly if the white line at the edge of the road is worn and patchy or broken up by patches of flood water.

[santa]

I wonder if strong electrical fields effect these systems. My DAB won't work passing under high tension wires.

My DAB usually looses signal when I meet a big lorry, which is a bit annoying.

[santa]

The LDW and auto dip / full beam switching are both controlled by the same camera. The Forward Sensing Camera (FSC) determines the conditions ahead of the vehicle while travelling at night and detects traffic lanes. The following systems also use the Forward Sensing Camera (FSC) :-

- High Beam Control system (HBC)
- Lane Departure Warning System (LDWS)
- Smart Brake Support (SBS)

The timing in which the system switches the headlights changes under the following conditions (some but not whole lot in the manual) :-

- When there are reflective objects in the surrounding area such as reflective plates and signs.
- When visibility is reduced under rain, snow and foggy conditions.
- When driving on roads with sharp curves or hilly terrain

If the LDW warning light is turned on, it indicates a possible malfunction of the system. Perhaps this happens when the forward sensing camera isn't functioning properly due to the conditions above and thus both the auto dip / main beam switching and LDW will be affected at the same time.

It must be the hills in the area that's causes the system to malfunction. Even though it's only for 3-400 meters.

[st3v3cx-3]

It must be the hills in the area that's causes the system to malfunction. Even though it's only for 3-400 meters.

In my part of the UK, a 300-400 metre hill would be considered a mountain