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Adaptive Main Beam Assist Inoperative

12K views 7 replies 3 participants last post by  Goody99  
#1 ·
After longer drives >30 mins I get the adaptive main beam assist inoperative warning on my dash. Then all manner of dashboard lights including fog light, main beam, low beam and a red warning symbol flash on and off intermittently. The fuel gauge also sometimes reads nothing and i've even had the speedo / revs not work!

While this is happening the indicator lights on dash don't turn on although indicators on the outside of the car are still functional.

I'm at a loss as on shorter journeys i've never had a problem and all systems function as they should.

Any help would be appreciated!
 
Discussion starter · #5 ·
See these threads, and more importantly, let us know if/how you solve it.





Thanks, i'll do some digging
 
Discussion starter · #8 ·
Did you manage to sort out this issue as it’s happening to my CLA 2016 on and off now
I tried the suggested fix of cleaning the grounding point under the bonnet but it wasn't the issue.

Tried changing the main battery and issue still there.

Decided to check the aux battery behind the front passenger carpets and found damp on the floor which i think was corroding the grounding point there.
Left the foot heaters on full with the carpet pulled back so it dried and it seemed to fix things temporarily until got damp again.

Water ingress from the rear air vents is most likely from what i can see on other threads as it's a common issue.

Hope this helps