Hey guys!

Long story short: My car has had a dodgy repair of the DRL lights and parking sensors. The sensors never worked when i bought it and i thought it was an easy fix. - i was wrong.

After i removed some panels i saw that something was not right. It seems like my car has had some kind of weird repair where the one who repaired it has cutted not only in the parking sensor cable harness but also in the cable that goes to the sam unit and replaced it with some dodgy connector.. Not only have they just twisted together the wires and used electrical tape they have also not included the first/last parking sensor cable!! So in my parking sensor harness there is only 5 sensor cabels where it should be 6..
I asked first on a w212 group chat on Facebook for some advice and after some discussion seems like i have two options.

Option 1. Get a wiring diagram and try to fix the cable by soldering the cabels.
Problems: I don't have a wiring diagram. And the fact that my parking sensor cable harness does only have 5 sensor cables instead of 6 makes this harder or even impossible?
See below

Option 2. change the whole stretch of cable that goes from the sam-unit to the parking sensor wiring harness and also changing the wiring harness itself.
Problem: According to a guy it is pretty difficult to pull the cable trough the engine bay and i might brake something else while doing it. Second I can not find what the cable that goes from the sam down to the fron right wheele where it connects to the drl/parking sensor harness is called or what part number it has. Only found out it is called "loom something.

So what i ask is if anyone can give me any advice or can help me look up what the cable is called in WIS for example?

Thanks in advance

// Alex

 

Wow, what a rat’s nest. Option #3- live with it.

 

Here is what parktronic harness looks like. I understand you have WIS it will include instructions for parktronic & engine harness replacement (search each respectfully). EPC will provide correct part #s for your VIN but I believe parktronic harness is 2125405610, 4 center sensors 2125420018, 2 outer sensors 2125420118, and engine harness 2125842381 viewed here: https://www.ebay.co.uk/itm/NEU-MERCE...8AAOSwaz9cswCw you may be able to identify missing connector. STAR wiring if included with your program will provide wiring diagrams, connectors, etc.

 

I'm inclined to go with @KEY08 's option number 3... as long as there is no persistent dashboard error.

Good luck with the repair if that is the route you go. But a word of advice regarding Mercedes - nothing is ever easy.

 

haha funny, Of course i could live with it. But firstly that is not a challange and i will not learn anything. Second i do have another car so this one can stay on my driveway for a year if i want to. It is always fun to challange yourself.

 

I hate it with folks butcher a repair job like this.

Yeah, that's the spirit. If you have the time, make it right. Keep us informed.

 

thank you for your reply! I think now i will try to repair the cables instead of change the whole harness from the sam.

Regarding WIS, i just bought it so it is still very strange and confusing. I will probably learn after a few weeks.

Another wired thing was that i found two radars inside the bumper, at least what it says when i google the serial number. After searching a while for parking sensor harnesses it seems like all cable harnesses i find has 6 parking sensor cables, one cable to this sensor/radar thing i found and two cables of a adapter with 2-pins(same as my harness). These cables with adapter of two pins are connecting to some blue connectors that are located to the crash bar. I do not know what these are for eighter.

I don't know if they have taken the harness from another model and tried to install it in mine or what these two sensor/radar purposes is to my car thus i don't find anyone else that has two of these in their w212. Is it possible to skip these with a new harness?

Any advice?

 

or maybe i was to quick.. seems like i found one with the same specifications, so i can connect the two boxes. Does anyone know their purpose on my car? Seems like it is supposed to be related to Distronic/adaptive cruise control, but i dont think i have that in my car because i dont have anything behind my grill
https://www.ebay.co.uk/itm/224120292099

 

Those are the blind spot sensors. These fail due to corroded pins/wiring all the time and can cause additional problems with the bus. I think the previous owner must have been trying to repair wiring and connections at those blind spot sensors that had failed. Hence the splices.
Well,take your time then and I’m sure you will sort it. Look on this site for blind spot sensor issues and you may find some useful threads to help you along.
You are in the rear bumper area correct?

 

Just Guessing here, but my buddy lives in a gated community in Palm Beach and they wire in a gate sensor to their cars that look an awful lot like that TYCO module in the first picture, do you guys have gated communities or secured facilities in Sweden?

 

No i am in the front bumper
Are you sure about this? Forgot to mention that i found signs of repair on the inside of the front bumper on the right side (just in front of the cable harness). So my guess was that it has been in an accident or someone has backed their car into this one.






just took some pictures of what i think is repaired.

 

My car was imported from Germany to Sweden in 2013 or 2014, but Sweden does not have gated communities and i don't think Germany has it either. Qualified guess though so thanks!

 

I believe those radar sensors in the front bumper are used for parktronic with parking guidance (i.e. parallel parking) and distronic. Maybe OP doesn't have distronic (lack of sensor in grill), but has the former.

 

Parktronic would be my guess as well.. but I didn't know how far back they offered that in the W212 line.

 

Yes, my '12 has parktronic and thinks it can park itself, I have four sensors in front and two on the fenders, I do not have Distronic, I found the one module the OP has but not the other one.

 

I agree, repair harness. Front bumper, install correct harness, sensors, etc. per VIN.

 

WIS/EPC can take some getting used to. I just bought another CD set to replace the 2015 version I had. Used on a laptop dedicated to the garage.
You can Google "Mercedes WIS Instructions" and look on a site autopodaci.com if I remember right. Has a pdf download of instructions that are helpful.
In your case if you can get to the wiring diagrams they will help give the overall picture of wiring/connectors/modules in the circuit along with any reference voltages.

 

Parktronic and Distronic has been around since the W211 back in 2003. It does get better over time. The W211 just gave you the distance, the W212 did parking guidance and in 2014+ actually did the parking.

 

I was thinking of the self park feature of the facelift and up.. my bad.

 

Thanks alot! Just ordered a wiring harness. Looked like it had all the connections. It w as a from a 2013 car though, so hopefully it works. Probably have it in a week