It is a 2002 C class with regular xenon headlights.

I took the car in to fix the air pump problem, dealer replaced the air pump, front SAM and relay, flushed the error codes and flashed with new software.

I always have my headlight switch set to AUTO position, but now when I turn on the ignition, the headlights are always on even under bright sunlight. The headlight sensor doesn't respond to ambient light anymore. I also observed the way auto leveling function acts differently. When I started the car, the headlights used to go up and down, but now it goes down then up.

Went back to the dealer several times, they even replaced the front SAM unit again as they suspected it was a Canadian version (they have DRL), but still can not figure out what's wrong. Any suggestion on how to fix it? I've checked the lighting configuration from the steering console, making sure it is not set to CONSTANT, everything is fine there.

Hi,

I would think that would be a coding problem in the Lamp Control Module rather than the Front Sam.

HTH

Alan