How-to DIY guide to retrofit Euro tail lights on North American Taycans

[whitex]

I think we need a "I fainted reading this" emoji reaction.

Dang, I forgot to add a warning about needing to keep your hydration and stamina up to get through a long post like this. I think I beat @daveo4EV for the longest single post.

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[DerekS]

I completely admire your dedication and commitment, and the thorough documentation you painstakingly provided.

I myself would never attempt something like this; doesn't it basically make the car street-illegal in the US? They changed those taillights for a reason, I assume...

 

[whitex]

doesn't it basically make the car street-illegal in the US?

IANAL but AFAIK it does not automatically make the car street illegal. It's not different than replacing any part of the car with non OEM part. If that part not not make the car violate regulations, you're good, even though that particular configuration was not tested as part of the car's homologation. To give a simpler example, imagine changing a stop signal light bulb in you older cars. Say you swapped an old incandescent bulb with a an LED one. As long as the bulb is emitting sufficient light (not too much, not too little) outside of the car (past the lens), the car is still street legal. Note that "outside the car" is an important distinction because even if your light bulb produces identical amount of light but in the wrong place (bulb is different shape), the plastic lens for the lights might not focus on the light source any more, so the end result is that the light looks a lot dimmer on the outside. Other examples could be putting in a 5 point seat belt system, using a non-OEM windshield, adding a roll cage, heck even adding an aftermarket spoiler. Manufacturers do a homologation with a particular set of parts on a car because it's cheaper than testing every single car coming off of a production line.

In this case I doubt the amber lights on the Taycan violate any US rules. Model Y has smaller amber turn signals (also a straight line) and they are legal.

They changed those taillights for a reason, I assume...

Two most common reasons for manufacturers to use red stop/turn signal combo are:

1. Cost savings, using the same bulb and wiring for both stop and turn signal, or at least saving on the single color plastic lens instead of dual lens in different colors
2. Esthetics - somehow amber lights on the back fell out of style, and are considered unattractive by manufacturers. Note how most manufacturers don't market with pictures showing amber lights glowing on the back, as well as they try to hide them behind clear lenses so you can't see yellow unless they are on.

I don't know exactly why Porsche did that, I would say reason #2 above is most likely, maybe partially #1 too - only one color of LED to put in the rear light saves on parts management/supply management cost (red LEDs also tend to be cheaper than amber), plus they saved some money on wiring (even 10 cents per in auto manufacturing is a big deal, I work with some and have lost fights over pennies, escalated to high VP level).

PS> Should I ever want to swap it back, it's ~30 minutes of work start-to-finish. Put in original lights (7 screws, 4 connectors, one clipped panel), cut the added wires if needed (would have to check if they would interfere with US lights), recode BCM2, all done, back to US lights.

 

[Leawood CT]

Just amazing work @whitex. Just wow! Also, I am once again left wondering what it is I do with all my time...

 

[ZenicaNC]

Wow. That is a great write up. While it doesn't appeal to me, I can appreciate the effort you put into doing this. The last time I did soemthing like this was to switch a 2 dr Acura Legends lights to the JDM version. Those lights really made the car pop. This change is more subtle. If I wanted anything from the EU version, it would be the matrix function of the headlights. Beyond that, the EU version doesn't have anything else I'd have use for.

 

[mystermykee]

I finished wiring the car over the weekend, and unlike @whitex both of my BCM2 connectors (black connector pin 2 and brown connector pin 7) had wires present. Sure is nice to have a full compliment of amber signals, much better than North American red.

 

[whitex]

I finished wiring the car over the weekend, and unlike @whitex both of my BCM2 connectors (black connector pin 2 and brown connector pin 7) had wires present. Sure is nice to have a full compliment of amber signals, much better than North American red.

Congrats! I bet it feels great to finally get to the end of your months long retrofit adventure.

Fyi, I never did figure out where that existing wire went. [EDIT: I did figure it out, see post #24 below]. When I disconnected it, no errors or warnings were shown, and all turn signals still worked fine. I left it connected. My best guess is that either it's going nowhere (they reused some harness originally intended for something else that contained that extra wire - my car was build during supply chain shortages), or perhaps it was intended for the custom Porsche bike rack? This reminds me, I need to add a warning for anyone using or planning to use the OEM bike rack or anything else that plugs into the trailer plug possibly counting on North American stop/turn signal combo - warning added to post #1.

 

[mystermykee]

Congrats! I bet it feels great to finally get to the end of your months long retrofit adventure.

Fyi, I never did figure out where that existing wire went. When I disconnected it, no errors or warnings were shown, and all turn signals still worked fine. I left it connected. My best guess is that either it's going nowhere (they reused some harness originally intended for something else that contained that extra wire - my car was build during supply chain shortages), or perhaps it was intended for the custom Porsche bike rack? This reminds me, I need to add a warning for anyone using or planning to use the OEM bike rack - it might need to be converted to Euro lighting too.

It feels great! Thanks for your help during these past few months. I would say it is the second best mod just after inkl beam.

 

[whitex]

Adding a warning/side effect.
It took me a while to figure this out, but there is one side effect of reconfiguring BCM2 to Euro tail lights. It turns out the pins from BCM2 which control the Euro center turn signals are used in the US for the trunk exit lights/buttons (US only feature, not present in the rest of the world). This means that recoding the BCM2 to non-US function will disable this functionality. This also explains why I found one of them connected on my CT (only front trunk), and others have found both pins connected on sedan (front and back trunks).

Added to main post WARNINGS section as well.

 

[hatysz]

Hi guys i just made a retrofit in my taycan sedan. I made one thing differently. I change the wiring connectors from us to eu. I bought them on aliexpress. cost around 5$. You need to remember that one connetor in left lamp is not 6 pin but 8 pin!
It is very easy to change them. You can buy special keys to remove pins from connectors or just take 2 wires and shape them and make them fit.

 

[whitex]

Hi guys i just made a retrofit in my taycan sedan. I made one thing differently. I change the wiring connectors from us to eu. I bought them on aliexpress. cost around 5$. You need to remember that one connetor in left lamp is not 6 pin but 8 pin!
It is very easy to change them. You can buy special keys to remove pins from connectors or just take 2 wires and shape them and make them fit.

I am curious. How did you end up with a US spec Taycan in Poland (part of EU)?

 

[hatysz]

I bought one on iaai and shipped it to Poland It was cheaper than buying one in EU. But quite risky because you don't know what are you buying. Mine was with salvage certificate. Porsche told us that we need to replace the battery and few other stuff. They were horribly wrong. When we inspected the car here, the repair took us one day and 200$ (one cut wire in powersteering caused massive fault for BCM)

 

[whitex]

I bought one on iaai and shipped it to Poland It was cheaper than buying one in EU. But quite risky because you don't know what are you buying. Mine was with salvage certificate. Porsche told us that we need to replace the battery and few other stuff. They were horribly wrong. When we inspected the car here, the repair took us one day and 200$ (one cut wire in powersteering caused massive fault for BCM)

Did you end up changing the charging ports as well?

 

[hatysz]

Did you end up changing the charging ports as well?

Yes i have changed them to type 2. Parts cost was 800$ but work was almost 2000$. Did not want to change them by myself.

 

[JTMC]

@whitex Very grateful for your guide. I wonder if I could ask you a bit of a reverse engineering question?

I am in Europe and I recently, stupidly, managed to buy a US tail light by accident. By the time I become frustrated and ground off the port "keys" ,confused as to why it didn't fit, it was obviously too late to return it.

Connecting it, the light works fine but gives me right and left turn signal errors (the inner turn signals are not illuminating, only the outer ones). Seemingly the wiring of the US plug is active on different pins.

Any idea which pins I would have to change or splice from a car-side Euro plug to get the US light turn signals to light up on the inside parts?

Presumably no coding required?

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