Hi guys,

I have a 2014 w204 c300 sport 4matic. From the factory it had halogen lights. I bought the depot projector housings and a DDM canbus (white boxes) HID kit. Besides having the worst time ever getting those low beam covers to go on and twist shut everything went smoothly.

Then I got to test them and get the wierdest problem I just can not figure out and really would appreciate some help on. Please.


1.The C led DRL works just fine on both lights.
2. Turn signals work fine on both lights.
3. Both projectors (hid bulbs) will work on high beam without issue.
4. Only the DS halogen bulb (in between the c and projector).... I guess its a way to illuminate directly to the left and right of the car...... in any case only the DS one turns on with the high beam even the PS high beam works just fine, but the halogen bulb wont turn on for it.
5. The PS low beam will not turn on, while the DS low beam has no issue whatsoever
6. The bulbs for the sidemarkers are in an on. Only thing not connected is the bumper DRL bars (could that be an issue?)

I have tried key in an out, car on or off, unplugging and replugging everything in multiple times, seeing if anything isnt connected in the headlight and even unplugging and replugging that in. What am I missing?

Are there any fuses that control the headlamps seperately? Any chance a module has some code that needs to be cleared for it to work? Any tests I can do? Battery reset do anything??
It got dark so I couldn't connect the bumper drls on quickly to see if that could be it, but I dont see why it would be.

Any help would be greatly greatly appreciated.

 

I figured out the issue. To help anyone else out in this perdicament in the future here are 3 common causes of the issue.

1. My solution was the low beam pin on the headlight poping out and back inwards of the headlight. It always appeared popped out when initially checking but as soon as the connector was attempted to be pushed on it just pushed back into the headlight creating no contact. I pushed the harness from the inside out to pop the pin out and then used needle nose pliers to pull on it effectively till it clicked in.

2. The next most common issue is there is a low/high beam control board that is a 6 pin molex style connector in the headlight accessible from the high beam side. This little module is wrapped in black shrink wrap and is a small rectangle. This fails. I swapped mine back and forth and it didnt change anything so it wasnt my problem. But after extensive digging I found this to be an issue on other similar bi xenon depos and found its also sometimes common on these based on some companies trouble shooting videos.

3. Lastly you have check the SAM module on the car is operating correctly. Usually you have other erratic issues pop up also.

Hope it helps someone in the future.