LED adaptive headlight / high beam failure warning

[Karlos70]

Hi all,

My 2018 435d is coming up with high beam failure / adaptive LED failure warnings but the high beam seems fine. I don't know how to check the adaptive function but visual inspection of the high beam shows it is working and it's passed 2 x MOT's.

On the last service I was told one of the LED's had failed = £2k for a new unit. I might be clutching at straws but with high beam working that's making me think (hope) the warning might be bogus?

Is it likely to be a new lamp unit needed or is there something else to check first?

All advice appreciated.

[Greydog]

Morning Karl

Welcome to the Forum

First try the simple things make sure nothing is obscuring the camera on the back of the rearview mirror and it's lens is clean, next disconnect the battery for at least 20mins that should reset everything.

If your still getting the fault a Diagnostic Scan is the way forward you need someone with a BMW capable system 

Main Dealer is obvious but will be the dearest so check BMW Specialists near you and good Independent Garages. The diagnostic should identify where the fault is the next trick is fixing it.

Good Luck

Dave

[Karlos70]

Hi Dave,

Many thanks for your quick reply. I've checked and cleaned the camera and will disconnect the battery tomorrow as suggested.

The high beam assist seems to work as it should turning on and off, although it does turn high beam on in what I would consider quite well lit areas. High beams light the road as you'd expect. Just the 2 warnings of left high beam failure and adaptive failure.

Main dealer didn't want to know when under warranty. Independent said LED failure - we can get you a new unit for £2k. Not convinced as it seems to work despite the warnings. Will get a 2nd opinion.

Best regards

Karl

[Greydog]

Hi Karl

As the lights are working and from your description correctly it could be a plug or pin that's a little gungy or possibly a software glitch

There is a register of BMW Specialists check it for ones near you I would check them out and get a proper diagnostic scan done as warnings are often a symptom not the cause. The Battery disconnect is actually something that Dealers do to clear faults so may work.

Dave

[G1000]

20 hours ago, Karlos70 said:

Hi Dave,

Many thanks for your quick reply. I've checked and cleaned the camera and will disconnect the battery tomorrow as suggested.

The high beam assist seems to work as it should turning on and off, although it does turn high beam on in what I would consider quite well lit areas. High beams light the road as you'd expect. Just the 2 warnings of left high beam failure and adaptive failure.

Main dealer didn't want to know when under warranty. Independent said LED failure - we can get you a new unit for £2k. Not convinced as it seems to work despite the warnings. Will get a 2nd opinion.

Best regards

Karl

I have the same issue on my 340i (17 plate). It first started last winter occasionally. No problems during the summer, but now it is every time it rains or has rained, particularly if cold and dark. If I use high beam it works fine, but then I may start to get adaptive headlight failure warning (again as far as I can see the adaptive headlights still work). Would love to know if disconnecting the battery works. I figured a loose connection or that a rodent keeping itself warm in my engine bay has had one nibble too many on one of the wires.

Cheers

Gareth

[Karlos70]

Evening,

I'll be disconnecting the battery in the morning and will report back.

Flashing the high beam a dozen times clears the error. Also the last vehicle check report shows rear headlamp levelling sensor rod seized. Maybe a cause.

I'll check the directory if battery disconnection doesn't do the trick.

Cheers

Karl

[Greydog]

Karl

If you have a seized level sensor arm either change it or lubricate it as it really could be your issue. Fix faults first other wise trying to reset Fault Codes is a waste of time as they will just return. As I understand it each Headlamp has 3 modules (1) a main Headlamp module (2) a Headlamp Control Module (3) a Cornering Module make sure the plugs are clean unplug them a spray with Contact Cleaner and reconnect making sure they are seated correctly

Then try disconnecting the battery to clear faults

Dave