Just joined because I have a build on my hands that I want to execute as best as I can.
I’m exploring a project where a classic Porsche Tiptronic TCU needs to operate correctly with a modern drive‑by‑wire standalone ECU.
I’m looking for an automotive embedded systems engineer who can design a small CAN/analog signal gateway to emulate the factory ECU signals expected by the TCU.
This is an electronics/signal‑level project only (no transmission internal work).
I’m currently scoping feasibility and the right approach.
For context, it’s a 1995 Porsche 993 Tiptronic, where the TCU will only talk to the factory DME. Would it be possible for a new ECU to be able to provide the TCU with the signals it expects? Or would this be along the lines of a microcontroller patching the ECU to the TCU?
Please guide - lol, it took me hours to be able to formulate what I wanted to ask… so, I’m not very technical. Just hopeful.
You’re looking for something to take in CAN (from an ECU) and send out a 0-5v value for ingestion into the TCU?
I’d bet a PDM could do something like that. I’ve not seen a PDM that can do analog out, but you can mimick that by using PWM to feed another ‘block’ that puts out 0-5v (or whatever is desired)
My questions - how do we deal with signal lag, error states, and shift quality?
So, the signals the TCU receives from the factory DME are as follows:
-RPM signal
-Fuel consumption signal (Ti-signal/injection signal)
-Throttle potentiometer signal
-Ignition retard command (TCU to DME)
-Emergency mode
I’ve written to quite a few places (KC Performance, Adapt Motorsports & Motec - I’m located in the UAE), and no luck as yet.
Would an AFM ECU like ECUMaster Pro 8 or Motec be able to send the correct signals to the TCU?
FYI - no standalone TCU option available for the ZF4HP22 transmission as it’s the earlier electro-hydraulic version. This would breathe new life into 964 & 993 tiptronic cars.
The problem is not if an ECU like Emu or extension device can send it…sure it can. But the problem is to have the detailed informations what to send…what the TCU is expecting. U need a CAN description file for this vehicle.
Do u have the informations what needs to be emulated?
But the problem is to have the detailed informations what to send
I completely agree with this.
This is a large undertaking for even someone more technical.
A trans swap might be in your future - labor to figure all this out isn’t going to be very economical. It’s an interesting problem. I’d love to see your solution come to life somehow!
I want to execute as best as I can.
I wish there were more people like you in the world!
Thanks everyone! This is all very helpful, and of course, I want to keep the scope realistic.
From my understanding, the Tiptronic TCU mainly relies on a limited set of engine signals from the DME. Reiterating, these signals are analogue.
Engine speed (TD / RPM) – simple to replicate
Throttle position (TPS / T‑MOT) – simple to replicate
Injector pulse / fuel signal – more complex; possible via a microcontroller/pulse generator working with engine RPM?
Ignition retard request – most complex element of this exercise
Tiptronic variant coding - simple to replicate
The idea is not to reverse‑engineer the gearbox logic itself, but to confirm whether this known signal set can be cleanly emulated so the TCU behaves correctly with the expected signals it needs. Would this be possible with:
A modern ECU’s programmable outputs, OR
An “in-between” programmable unit/microcontroller/etc
The official technical data and wiring pinout signals between the DME & TCU for a 1995 993 C2 Tiptronic are available (transmission coding, factory manuals, etc.)
I’m trying to understand whether this stays a contained signal‑emulation task, or whether this mushrooms into a full-blown reverse-engineering conspiracy
Sincere apologies if I’m wasting anyone’s time here!
Sincere apologies if I’m wasting anyone’s time here!
I wish I could help more. These are the kinds of problems that scratch my itch.
I don’t have any experience with these platforms, but for anyone else here’s some data to help out:
Dubai, UAE. Hot as the sun these days. I have access to a solid garage I work with, but this hasn’t been done before, at least here. Most folks with 1998 (or older) cars hoard them, get them fixed for a Sunday drive with the “club”, and then shelf them for the next 6 months. I believe these cars can be driven daily, reliably, and outperform your expectations IF you modernize the entire package. This is easy to do with manual cars. This is seemingly NOT simple to do with tiptronic cars. For whatever reason, Porsche fitted the 964 & 993 with a very limited tiptronic transmission.
I think if this post can crack it, I can definitely provide my car as the testing platform, and share progress. Given how many Tiptronic cars are out there, this would address a very specific niche in the air-cooled market, and open the car up to the same level of engineering as manual cars can run.
Also the fact that KC Performance say they’re working on this right now, with a 993, is encouraging. I mean, they’re doing insanely technical stuff like PDKs in aircooled cars.
If KC Performance ends up not releasing something in the future, let me know.
Most of our work is R&D of control systems. This could be a fun project, but it would probably be a bit time consuming.
Wrote in to Adapt Motorsports as well, and they’ve build a plug & play ECUMaster Pro 8 system that plugs into the factory 55-pin connector. They haven’t tested it on a tiptronic though - and they’re still fine tuning the wideband oxygen sensor wiring.
