sherrych27

Hi guys so i own a w212 mercedes 2010 model converted / facelifted to 2015. Everything is running sublime however it has been few months since i am trying to search a solution to a problem regarding rear and front lights

the headlights stay on no matter what I do. Ideally when a car is parked only parking drls should be on but my car’s headlights get on too which is of course not a huge concern but really bothers me. Any help from this super helpful community shall be highly appreciated

S-Prihadi

When the conversion was done, is there any extra 3rd party electronics module involved ?
Once the hardware get contaminated by non MB ones, it will be more difficult to troubleshoot as there is no wiring information or hacking information from that 3rd party module.

I do no know how basic is you 2010 exterior light system, but if yours is the non CAN BUS one and converted to facelift model which the system is CAN BUS dependent,
a simple fault on CAN-BUS communication can mean the lights may not turn OFF when they should turn OFF.

To explain in simple term would be like this :
A non CAN BUS light system will depend much on mechanical switch to turn itself ON-OFF.
A CAN BUS light system is data or command activated from Rear SAM ( If facelift model ) . This command is digital bits, and not a mechanical ON-OFF.

This is why I ask : When the conversion was done, is there any extra 3rd party electronics module involved ?

sherrych27

I am so sorry sir but i dont understand what you mean by CAN BUS and am very apologetic for my lack of knowledge or if this question irritates you. Btw the car was converted 3 years ago. Can that help?

S-Prihadi

You then best go back to them who made the facelift modification, because only they know how things were wired and if there is any extra module/small computer assisting in that facelift process.
Any MB dealer can't even help you as they will refer to original MB factory wiring and in most instance the wiring is not 100% stock anymore

Left Coast Geek

CANbus is a digital communications bus, somewhat similar to but different than the Ethernet used for computer networks. Recent model Mercedes are heavily vested with CANbus control, I believe the facelift W212's have something like 6 or 7 different CANbuses interconnectingt he 30 or so computer modules. Old school cars, heavy power gauge wiring would have to run from the main power distribution (usually the fuse block) to the lamp switch, then to the high/low dimmer switch, and then to each lamp... With canbus, there's just one set of power wires to a whole section of the car, and the control stuff (low beam on! left turn signal blink! low beam off, high beam on!) is done with digital messaging over a skinny pair of canbus wires.

the facelift LED headlights on my wife's 2016 go way beyond this, the car commands them to aim left or right based on the windshield cameras estimation of where the road is going... high and low beams are managed with servo motors that raise and lower the headights instead of just turning on and off different lamps. In Europe, these same lamps do things like selective high beams where they can do a 'cutout' around an oncoming car while leaving the rest of the road fully illuminated, but that doesn't meet the antique US DOT headligth standards so the feature is disabled on US model cars.

this is the 'startup sequence' on my wife's 2016 E350 ILS LED headlights....