mraurora

2005 CLK 320 Cabriolet. 51k. Equipped with bi-xenon auto-leveling headlamps (not swiveling). Started the car one night recently and both headlights dipped down towards the ground and stayed there. It's been to three highly rated independent shops, and no one knows what's wrong. It's not throwing any codes. The shops all say the module is talking to the sensors on the axles. They say the sensors on the axles are within parameters (3 volts). They hook up the car to the diagnostic system to recalibrate, and they say the process seems to be recalibrating, but there is no physical motion of the projectors. Everyone is stumped. Anyone have any insight? At this point, it seems we'd just have to start replacing parts and crossing our fingers. The headlights have been manually raised so they're not pointing at the ground, but I'd really like to fix this "just because".

mraurora

bump

Anteater

Your problem is likely bad wiring inside of the headlights themselves. I have the same issue with my 03 CLK with xenons. There is a motor inside of each headlight unit that adjusts the leveling height of the xenon projector. With time, the wiring sheathes can go bad and create a short or the adjustment motor has gone bad. My only recommendation would be to buy a new OEM headlight or to disassemble your current headlight unit and replace the wiring/motor. If you go the route of disassembly, there is a kit somewhere online to replace the projector lenses which includes a leveling motor. I would not recommend buying used xenons as with time they will also have bad wiring/motor issues.

mraurora

Both headlights dipped at the same time. Could a wiring problem in one headlight cause both headlights to malfunction at the same time?

Anteater

I failed to read the part where both dipped down at the same time. Your wiring and motors are likely fine. The only thing I can think of then is if the link for the level sensors is broken. ie. the link connecting a level sensor to the front sway bar link and the level sensor connected to a control arm in the rear. It is also possible that one of those level sensors (there are 2 under the car) has gone bad without telling the car's computer.