There’s a bit of history to his one…
Driving home from work late at night, I hit a flooded road. The water came up to around the middle of the wheels, luckily no water came inside of the car! Upon inspection, one of the access covers had fell off the drivers side headlight, and water had got inside.
This cause two issues: drivers side day time running light failed after about a week, and secondly I have this error code on the dash, which came up immediately:
error: cornering light (AFS).
LED running light was just the ballast card, but the AFS is still an problem.
Now when I turn the car on, the passenger side headlight does the AFS ‘dance’, but the drivers side stays in the ‘safe position’.
I have a rough idea of how the system works, but have a few Q’s about how best to diagnose the problem.
My understanding is that there is a level sensor on each corner of the car, a ‘master’ controller behinds the drivers side glove box, and some amount of electrical gubbins in each of the headlights, that move and focus the bi-Xenons.
I’ve ruled out the ‘master control’, as it didn’t get wet, and I’d expect both headlights to be effected. But given the water came pretty deep, and got into the headlight itself, it could be with either something within the headlight itself (I’m assuming there are one or more motors, and probably other stuff??), or more likely (hopefully!) one of the level sensors has got water in the connector block and is goosed.
My main question is this: do all 4 level sensors feed into both headlights, or do the front and back drivers side level sensors control the drivers side head light, and likewise on the passenger side?
if it’s the case that all 4 sensors control both headlights, and it’s one ‘system’ rather that two systems (one for each side), then the issue would have to lie with the headlight, as it’s only effecting the drivers side, and a single level sensor failure would take out the AFS on both headlights if all one system. Hope that makes sense?
Given the failed drivers side has returned to the ‘safe’ position, I’m hoping that it’s ‘two systems’, and whatever moves/focuses the Xenon in the headlight is working, and has put it there in auto, as it has lost input from one or both of the level sensors.
the car ‘knows’ that it is only affecting the drivers side, as it is only showing on the drivers side on the car, on the screen on the dash.
Any help appreciated, I’m under the car this weekend doing the oil etc, so should be easy enough to pull a few plugs and check for water ingress/corrosion 👍🏼 But if anybody could save me any time, that’d be great!