GT Tail Light programming

[KfabR8]

It would appear that the 2011 YM cars have a different control system than previous years. - or the control system for the tail lights has been relocated to some spot that I can't access (yet) w/the VCDS system.

Since I know of a couple people on the board that are wanting to install the GT lights, I figured I'd start a diagnostic thread and walk through what I've been through thus far:

The GT tail lights have the Euro-spec amber blinker strip in them. You have to reprogram your car so that it recognizes this. If not, the amber strip will light up every time you hit the brakes and when you use your turn signal. It's piggybacked with the brake light.

When I discovered that I couldn't (yet) separate the system via the VCDS, I decided to go to the wire harness and pull the one line that controls the amber strip out of the plug. (you must have the correct tools to do this - do NOT just try to pull the wire out or you will, guaranteed, destroy the wire). This will allow me to drive the car w/o fear of LEO stopping me for funky lights.

Some quick checking and I have the wire harness mapped out
Plug (on the NA tail lights) has six leads:

1. Black - Tail Light Ground
2. Black - Reverse Ground (larger gauge)
3. Green - Reverse Activation (larger gauge)
4. Blue - Brake Activation. Resistance of 325K ohms
5. Yellow - this is the one I'll discuss in a minute
6. Red - Tail light activation Resistance of 290K ohms

Being that wire #5 (yellow) seems to be an open circuit I'm confused by what I'm finding. If the car didn't see a circuit here originally, then why is it now trying to report back an open circuit? The only thing I can think of is since the pulled lead (the lead that activates the amber strip - which is active; piggy backed on the brake circuit) saw a load now the control system wants to see a load? Makes no sense...

When I pulled the lead that activates the amber blinker out of the harness, this should have "informed" the control that there was an open circuit (as per the NA tail lights). No, of course not. I'm getting left and right blinker codes on the dash display. It thinks there's a lamp out. - think similar issues with the LED license plate lamps.

It now would appear that the car is searching for a signal light. I have to wonder if the GT tail lights have a different resistance in each circuit?

I'm not ready to pull a wheel and inner fender liner to see what the GT's plug maps out to (yet). When I do, I'll post findings.

I'm waiting on Alex at Europrice to get back in touch with me - he has a VCDS Ninja working on some projects that have had similar issues. Hopefully he'll be able to help me hack into the system and find the coding for separating the running/brake and signal lights. I'll report back as soon as I get more info.

[ktdre]

I definatly am no expert at this but i recall reading something which might work so just going to mention it (might be completely off). People who have tyre pressure sensors and change rims used to get errors when they change the rim. They did something (cant recall what but it is on this forum and involved a 20mile drive to rest them). Maby originally your car was set without the ambers there so your cars computer was set to them being not there. Once you connected them the computer detected them but was not controlling them right (which is the programing part u r trying to sort out). Now that you pulled the wire the computer already is set to them being there and you need to somehow reset the computer at which stage it would check if it is there and if not then default to not there again. I dont know if all this makes any sense but just said i will put it out there. Good luck kfab.

[KfabR8]

I understand your thought pattern and it does make sense. Alas, it doesn't work.

[Europrice]

You've got a mail to go through. I have an idea and what the oddest thing of all is is that there is a Pin 5 at all on your new car. US models are not supposed to have this at all, even early ones. So technically you never should have been able to make your old EU taillights on the grey car work, but they did.

So just to get you going I want you to test a wiring solution.

Next then is to see if we can't dig up more info on these 2011 BCM (Central Electrics) modules because they are most definitely different. I get that not so happy feeling the secured area is where we need to go and since that access code didn't work we've gotta dig elsewhere. Then again it could be in the coding, but we don't have a map of that coding yet, at least I can't check here as I don't have a label file for that module.

I want to get you set with a non-pullover taillight function, no errors and then dig into the module.

Thanks!

[sapien]

So the GT lights can be used normally in the US without any of that amber strip programming?

[KfabR8]

Yes. Being that I've not looked at my 09's plug, I don't know the wire layout, but in the 2011, I had to move one pin in the plug. Now they work just like normal NA market lights - just no amber strip (which is a bummer!).

If you just plug them in, the entire light ass'y, including the amber strip, blinks with turn signals and lights up with brake lights.

[Yspokes]

Kfabr8.... were you able to resolve the wiring/programming issues, or did Audi indeed switch BCU's for MY 2011? Inquiring gear heads want to know.

[KfabR8]

I've not looked into this yet - been exceptionally busy the past three weeks.

I had the inner fender liner out of the '09 last weekend, but my focus was on fixing (another) leaking turbo coolant line and I totally spaced taking a look at the plug. I think the '09 has six wires running to the plug as opposed to the five in the '11, but until I get back in and look, I'll not know...

[Yspokes]

Oh, that's right! You've been out racing with "the Boys". Never mind..... some things take precedent.