As most of you probably know by now, the Launch Control feature was removed from the DSG's Transmission Control Module (TCM) for all US-spec 3.2 TT's.
I've been trying to figure out how this was done, and after working with HPA on getting their FT400 turbo kit installed in my TT we've all learned a lot about what exactly happened:
1. Lucky first few 3.2 owners: the first 150 or so US-spec TT 3.2's made it on this side of the pond with the same TCM as the Euro-spec TCM. Therefore, the Launch Control feature was enabled as it was in the code and nobody touched it. I actually test-drove the first TT that made it to California, and even though I originally thought LC was disabled, it was actually there and working like a charm. Too bad I wanted to special-order mine..
2. Port hold: Sometime in late 2003, Audi of America imposed a port hold on all 3.2 TT's as a "defect" was found with the DSG. What truly happened is not confirmed by anyone, but we believe the port hold was mainly created to disable the Launch Control in all US-bound 3.2 TT's. From that point on, all US-spec 3.2's had the Launch Control program disabled as the TCM is completely different - more on this later.
3. DSG Recall: sometime in early 2004, there was a recall on some early 3.2 VIN's as they found out there was a *real* defect with the DSG. Even though the rumor was that this recall was created as an excuse to disable Launch Control on those early 150 or so cars that "slipped through", there was actually a problem with the way the early DSG's were built: a seal was installed incorrectly causing the DSG to get stuck in a gear or not engage at all. This was also experienced in Europe, so we know that this recall was legit. *However* in replacing the problematic DSG's, Audi of America took this opportunity to install completely new TCM's along with the DSG itself - hence disabling Launch Control!
4. More than a code change: Beyond a simple reflashing of the DSG's TCM to disable the Launch Control program, Audi has created an entirely new TCM controller for US-bound 3.2's. This new TCM doesn't even have the capability of getting reflashed with the Launch Control program, because the code is completely missing. I had a hard time swallowing that, being a software engineer and such, but HPA worked long hours with Germany to find out that the US-spec TCM simply cannot take the LC program at all. What HPA ended up doing for my install is order a Euro-spec TCM overnight to complete the FT400 install, as they had promised me LC with the kit. The most painful part is that the TCM is encased inside the DSG so they had to drain the oil from the DSG, take it completely apart, remove the US-spec TCM and replace it with the Euro-spec TCM.
5. Paddle circuits too! Beyond the TCM being completely new for the US, the steering wheel was also completely rewired with a 4-wire harness, vs a 2-wire harness in European 3.2's. Indeed, the paddle circuits are completely different in that the US-spec ones are simply an on/off setup (short to gound), whereas the Euro-spec ones are in the same circuit loop with different resistors to act in different functions - more on this below. So HPA had to tear the steering wheel apart to remove the paddle circuit boards, solder some resistors on them and only use 2 of the 4 wires coming from the TCM. Wish I had kept those R32 aluminum paddle's circuit boards!
6. Manual Mode not acting like one: The DSG behavior was even tweaked differently in these new TCM's. In Manual Mode, the transmission would shift by itself just before hitting redline. Everyone who reviewed the DSG complained that this Manual mode was really not manual at all as it was *automatically* shifting for you before redline! This can be particularly annoying on the track where you want to hold a gear on the apex of a corner.. When HPA replaced the TCM in my DSG, they also increased the redline to 7150 RPM. The beauty of the Euro-spec TCM is that now, Manual mode is truly Manual as the DSG will hold a gear around 7000 RPM until you upshift, and not upshift *for you*.
7. Manual Over-ride: One other difference to the US-spec TCM is that, when either in Drive or Sport mode, the driver can always take over the shifting action manually with the paddles *however* this over-ride times out after 15 seconds or so. In the Euro-spec TCM, the over-ride does NOT timeout after 15 seconds, but keeps you in Manual mode *until you hold the right paddle for a couple of seconds!!!* So now I'm kicking myself for "erasing" the /OFF from my right paddle... oh well.