Albatrossboss

Hello All,

I have been chasing a short in the Driver side rear outer corner tail light for awhile and have finally had the time to really dig in to the issue. I need some clarification on the wiring diagram for the wiring harness.

The outermost LED strip that is used on North American market vehicles, goes in and out. I have tried standard troubleshooting practices by jiggling one wire at a time, looking for bare metal, bending/flexing the wires to see what happens, etc. The longest period of time those actions have worked is usually around a 45 seconds.




Outermost LED strip is the area of interest. (not my actual light, borrowed from EBay)

I have been through the wiring diagram and can not figure out which wires run to this LED strip. None of the wires in the harness I was messing with are labeled on this diagram.



All help is greatly appreciated.

dvs_dave

I had the same problem. The fault lies in the ECU within the lamp unit itself, not the connections. Figured this out by swapping the ECU over from the the other side lamp which was working normally, and then it worked fine. Unfortunately they are interchangeable as the ECU boards are shaped to suit each side.

Replacement ECU boards are not available, so unless you know how to fix them it's a complete new lamp unit for $$$.

Or do what I did and disconnect the corner marker LED's inside the lamp unit on both sides and you're good to go. No error codes, and the "Euro look" for free!

MP4.2+6.0

FWIW, single (overall) components of tail lights are often found on EBay, including for D3s. You just need to get pre or post facelift, know which of the four components you want, and get the North America or Euro variants depending on your locale.

Albatrossboss

Thanks for the info, after messing with it some more this weekend, using Deoxit D5 on the connectors to flush the possible gunk (virtually non-existent, but the flushing fluid was a darker color so it must have cleaned something) the light is now working, fingers crossed it keeps working. Looking at Ebay just a moment ago, I found a used unit for $114 that could be used as a donor unit since the outside lens is in rough shape.