[cwolfe12898]

Hello all, I purchased my f30 a few months ago and today noticed that the left inner turn signal isn't working, the previous owner did it and looks like they did a decent job. But I'm clueless as to what the issue is. I don't know if he installed them wrong or the light has went out? I don't know much about wiring. Anybody know where I should start? Before they were not coded to be retrofitted and I coded them with bimmercode which fixed the flickering issue. I know coding didn't mess them up as I did a backup and the problem still persisted. Any help is greatly appreciated.
This looks like the same issuehttps://f30.bimmerpost.com/forums/showthread.php?t=1400959

[Oksamit78]

1. Was the turn signal working earlier, after you took over the ownership?
2. You need to find out if this upgrade (you car is not meant to have these tail lights from the factory) was done using BMW upgrade wire harness that connects the upgraded lights to the REM direct for each of 4 turn signals (2x Lefts and 2 Rights) or with aftermarket wiring when the inner turn signals are connected to respective turn signals in the outer light assemblies. The issue you have linked to in your post describes upgrade with aftermarket wiring. Which ever case, you need someone with a basic electrical knowledge to test the wiring.
3. If the upgrade wiring used is OEM and there is no power coming to the light, the issue could be in REM (Rear Electrical Module). That would require taking the car to dealer and testing the REM first at certain service fee. If REM fails testing - might face REM replacement costs.
4. It could be that the light was not installed correctly and over time had accumulated moisture inside and as a result the PCB board inside the light had developed corrosion damages. I'm currently fixing the corrosion damages to the inner light (M Performance version with clear lens) for a friend of mine and his F31. I had to cut open the assembly in order to reach the pcb board. This is not a trivial task like changing a burnt out bulb. These assemblies are not meant to be opened up. If the wiring checks out (power arrives at the light) then you are facing light replacement. You will need to search for used light (OEM new, eBay used, junk yards with used, etc).

[cwolfe12898]

1. I don't know really haven't checked them before
2. The wiring next to the battery looks oem to me, i will see if I can make sure
3. I think the REM is ok
4. I don't think its moisture, never saw any moisture in them

Could it have something to do with wire tapping? What should I look out for if so, I've noticed they inner ones need to be wire tapped because the pre-lci inner tail doesn't have a turn signal

[Oksamit78]

Study pdf in the attached link.

This is OEM upgrade instructions using OEM wiring:
https://www.docdroid.net/8ieaEsN/f30-lci-rear-pdf

Then look at REM in your car and see if the new wires described on Page 8 of the document do connect to REM of your car using Pins 5 and 13 of A174 plug.

If those wires are not existent at REM plug, that means that the upgrade was done using aftermarket wiring which uses wire taps to connect inner turn signals to the matching outers. Look for the tap in the rear left fender. There could be a loose connection there that caused inner turning signal to stop working.

Good luck.

[cwolfe12898]

Ok thanks

[cwolfe12898]

Ok, so i guess it doesn't use bmw harness. Can you please tell me if the drivers side is tapped?

[Oksamit78]

Originally Posted by cwolfe12898

Ok, so i guess it doesn't use bmw harness. Can you please tell me if the drivers side is tapped?